question_slug stringlengths 3 77 | title stringlengths 1 183 | slug stringlengths 12 45 | summary stringlengths 1 160 ⌀ | author stringlengths 2 30 | certification stringclasses 2
values | created_at stringdate 2013-10-25 17:32:12 2025-04-12 09:38:24 | updated_at stringdate 2013-10-25 17:32:12 2025-04-12 09:38:24 | hit_count int64 0 10.6M | has_video bool 2
classes | content stringlengths 4 576k | upvotes int64 0 11.5k | downvotes int64 0 358 | tags stringlengths 2 193 | comments int64 0 2.56k |
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valid-phone-numbers | Bash cat grep | bash-cat-grep-by-ajrs-pc3p | \n# Read from the file file.txt and output all valid phone numbers to stdout.\ncat file.txt | grep -E "(^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3,3}\\) [0-9]{3}- | ajrs | NORMAL | 2021-07-02T05:20:01.996842+00:00 | 2021-07-02T05:20:01.996879+00:00 | 906 | false | ```\n# Read from the file file.txt and output all valid phone numbers to stdout.\ncat file.txt | grep -E "(^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3,3}\\) [0-9]{3}-[0-9]{4}$)"\n``` | 2 | 0 | [] | 2 |
valid-phone-numbers | this solution can not be more uglier :( but hey at least it works : D | this-solution-can-not-be-more-uglier-but-j6li | \tpublic static boolean isValid(String num){\n\t\t\tnum.trim();\n\t\t\tString[] tokens0 = num.split(" +");\n\t\t\tif (tokens0.length == 3) {\n\t\t\t\treturn fal | jerryJv11 | NORMAL | 2020-11-27T03:35:42.332222+00:00 | 2020-11-27T03:35:42.332256+00:00 | 595 | false | \tpublic static boolean isValid(String num){\n\t\t\tnum.trim();\n\t\t\tString[] tokens0 = num.split(" +");\n\t\t\tif (tokens0.length == 3) {\n\t\t\t\treturn false;\n\t\t\t}\n\t\t\tString[] tokens = num.split("\\\\-" );\n\t\t\tif (tokens.length == 3) {\n\t\t\t\tif (tokens[0].length() == 3 && tokens[1].length() == 3 && t... | 2 | 0 | [] | 0 |
valid-phone-numbers | Grep -E approach simplified | grep-e-approach-simplified-by-spenz-kru5 | \ngrep -E \'^([0-9]{3}\\-|\\([0-9]{3}\\) )[0-9]{3}\\-[0-9]{4}$\' file.txt\n | spenz | NORMAL | 2020-05-08T06:21:58.559327+00:00 | 2020-05-08T06:21:58.559381+00:00 | 639 | false | ```\ngrep -E \'^([0-9]{3}\\-|\\([0-9]{3}\\) )[0-9]{3}\\-[0-9]{4}$\' file.txt\n``` | 2 | 0 | [] | 0 |
valid-phone-numbers | grep -e solution is pretty straightforward to me, why doesn't this work? Any ideas? | grep-e-solution-is-pretty-straightforwar-srq9 | \ngrep -e "\\d\\d\\d-\\d\\d\\d-\\d\\d\\d\\d" -e "(\\d\\d\\d) \\d\\d\\d-\\d\\d\\d\\d"\n\n | justxn | NORMAL | 2019-07-28T06:55:58.441845+00:00 | 2019-07-28T06:55:58.441879+00:00 | 571 | false | ```\ngrep -e "\\d\\d\\d-\\d\\d\\d-\\d\\d\\d\\d" -e "(\\d\\d\\d) \\d\\d\\d-\\d\\d\\d\\d"\n```\n | 2 | 0 | [] | 1 |
valid-phone-numbers | grep -e solution | grep-e-solution-by-lei8c8yahoo-yivs | grep -e \'^[0-9]\\{3\\}-[0-9]\\{3\\}-[0-9]\\{4\\}$\' -e \'^([0-9]\\{3\\}) [0-9]\\{3\\}-[0-9]\\{4\\}$\' file.txt | lei8c8yahoo | NORMAL | 2019-06-20T01:52:23.525375+00:00 | 2019-06-20T01:52:23.525422+00:00 | 736 | false | ```grep -e \'^[0-9]\\{3\\}-[0-9]\\{3\\}-[0-9]\\{4\\}$\' -e \'^([0-9]\\{3\\}) [0-9]\\{3\\}-[0-9]\\{4\\}$\' file.txt``` | 2 | 0 | [] | 0 |
valid-phone-numbers | Using Bash regex | using-bash-regex-by-oxota-ro01 | \n#!/usr/bin/env bash\n\nwhile read line; do\n if [[ "$line" =~ ^((\\([0-9]{3}\\) )|[0-9]{3}-)[0-9]{3}-[0-9]{4}$ ]]; then\n echo $line\n fi\ndone < | oxota | NORMAL | 2019-06-07T05:45:35.421290+00:00 | 2019-06-07T05:45:35.421321+00:00 | 822 | false | ```\n#!/usr/bin/env bash\n\nwhile read line; do\n if [[ "$line" =~ ^((\\([0-9]{3}\\) )|[0-9]{3}-)[0-9]{3}-[0-9]{4}$ ]]; then\n echo $line\n fi\ndone < "file.txt"\n``` | 2 | 0 | [] | 0 |
valid-phone-numbers | Why is `grep -E '^\(\d{3}\) \d{3}-\d{4}$|^\d{3}-\d{3}-\d{4}$' file.txt ` wrong? | why-is-grep-e-d3-d3-d4d3-d3-d4-filetxt-w-83an | \ngrep -E \'^\\(\\d{3}\\) \\d{3}-\\d{4}$|^\\d{3}-\\d{3}-\\d{4}$\' file.txt\n\n\nError message:\n\n\nInput:\n123-456-7891\nExpected:\n123-456-7891\n\n\n\nHowever | tylerlong | NORMAL | 2018-05-29T08:53:41.960391+00:00 | 2018-05-29T08:53:41.960391+00:00 | 565 | false | ```\ngrep -E \'^\\(\\d{3}\\) \\d{3}-\\d{4}$|^\\d{3}-\\d{3}-\\d{4}$\' file.txt\n```\n\nError message:\n\n```\nInput:\n123-456-7891\nExpected:\n123-456-7891\n```\n\n\nHowever, the following works:\n\n```\ngrep -E \'^\\([0-9]{3}\\)\\s[0-9]{3}-[0-9]{4}$|^[0-9]{3}-[0-9]{3}-[0-9]{4}$\' file.txt\n```\n\nThe only difference is... | 2 | 0 | [] | 3 |
valid-phone-numbers | Filter Valid Phone Numbers Using grep and Regular Expressions | filter-valid-phone-numbers-using-grep-an-nyss | IntuitionThe problem is essentially about filtering lines that match specific phone number formats. Since the input is a plain text file and the pattern is well | suhrob_kalandarov | NORMAL | 2025-04-10T03:44:55.887697+00:00 | 2025-04-10T03:52:54.938301+00:00 | 38 | false | # Intuition
The problem is essentially about filtering lines that match specific phone number formats. Since the input is a plain text file and the pattern is well-defined, a regular expression is the most efficient tool to recognize valid formats.
# Approach
We use the grep command with the -E flag (extended regular ... | 1 | 0 | ['Bash'] | 1 |
valid-phone-numbers | easy bash solution to understand | easy-bash-solution-to-understand-by-prat-wr9v | IntuitionApproachComplexity
Time complexity:
Space complexity:
Code | pratik5722 | NORMAL | 2025-03-03T07:57:49.434122+00:00 | 2025-03-03T07:57:49.434122+00:00 | 450 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
`... | 1 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Easy Solution Beats 98.24% | easy-solution-beats-9824-by-rishabh_234-02q1 | PLEASE UPVOTE\n# FEEL FREE TO ASK\n# Code\nbash []\n# Read from the file file.txt and output all valid phone numbers to stdout.\ngrep \'^\\([0-9]\\{3\\}-\\|([0- | r_90 | NORMAL | 2024-10-20T16:52:04.132218+00:00 | 2024-10-20T16:52:04.132242+00:00 | 21 | false | # PLEASE UPVOTE\n# FEEL FREE TO ASK\n# Code\n```bash []\n# Read from the file file.txt and output all valid phone numbers to stdout.\ngrep \'^\\([0-9]\\{3\\}-\\|([0-9]\\{3\\}) \\)[0-9]\\{3\\}-[0-9]\\{4\\}\n``` file.txt\n``` | 1 | 1 | ['Shell', 'Bash'] | 0 |
valid-phone-numbers | USING GREP COMMAND | using-grep-command-by-ujjwalvarma6948-kvfl | //PLEASE UPVOTE IF YOU LIKE THE APPRAOCH !!\n\n# Code\n\ngrep -e "^[0-9]\\{3\\}\\-[0-9]\\{3\\}\\-[0-9]\\{4\\}$" -e "^([0-9]\\{3\\}) [0-9]\\{3\\}\\-[0-9]\\{4\\}$ | ujjwalvarma6948 | NORMAL | 2024-03-06T16:57:45.416155+00:00 | 2024-03-06T16:57:45.416187+00:00 | 553 | false | //PLEASE UPVOTE IF YOU LIKE THE APPRAOCH !!\n\n# Code\n```\ngrep -e "^[0-9]\\{3\\}\\-[0-9]\\{3\\}\\-[0-9]\\{4\\}$" -e "^([0-9]\\{3\\}) [0-9]\\{3\\}\\-[0-9]\\{4\\}$" file.txt\n``` | 1 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Number Validate | number-validate-by-abdulvoris-w1ja | Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time | Abdulvoris | NORMAL | 2024-01-10T19:20:25.190869+00:00 | 2024-01-10T19:20:25.190913+00:00 | 1,309 | false | # Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ --... | 1 | 0 | ['Shell', 'Number Theory', 'Bash'] | 1 |
valid-phone-numbers | Solution | solution-by-suraj_singh_rajput-b8qe | Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time | Suraj_singh_rajput | NORMAL | 2023-12-22T07:11:38.010009+00:00 | 2023-12-22T07:11:38.010039+00:00 | 15 | false | # Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ --... | 1 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Easy and simple :0 WOW (0_0) | easy-and-simple-0-wow-0_0-by-azamatabduv-deli | \n# Code\n\n# Read from the file file.txt and output all valid phone numbers to stdout.\ngrep -E \'^(\\([0-9]{3}\\) |[0-9]{3}-)[0-9]{3}-[0-9]{4}\n file.txt\n``` | AzamatAbduvohidov | NORMAL | 2023-05-13T13:06:27.535847+00:00 | 2023-05-13T13:06:27.535877+00:00 | 6,992 | false | \n# Code\n```\n# Read from the file file.txt and output all valid phone numbers to stdout.\ngrep -E \'^(\\([0-9]{3}\\) |[0-9]{3}-)[0-9]{3}-[0-9]{4}\n``` file.txt\n```\nThis script uses grep command with extended regular expressions (-E) to match the pattern of valid phone numbers. The pattern matches either (xxx) xxx-x... | 1 | 0 | ['Bash'] | 1 |
valid-phone-numbers | [BASH] using while and if statements | bash-using-while-and-if-statements-by-am-icko | \n#!/bin/bash\nfile_name="file.txt"\nphone_number_regx=\'(^[0-9]{3}-[0-9]{3}-[0-9]{4}$)|(^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$)\'\n\nwhile read line;\ndo\n\tif [[ | amresh564 | NORMAL | 2022-11-30T19:16:26.272570+00:00 | 2022-12-16T15:37:59.416202+00:00 | 136 | false | ```\n#!/bin/bash\nfile_name="file.txt"\nphone_number_regx=\'(^[0-9]{3}-[0-9]{3}-[0-9]{4}$)|(^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$)\'\n\nwhile read line;\ndo\n\tif [[ "$line" =~ $phone_number_regx ]]; then\n\t\techo $line\n\tfi\ndone<$file_name\n``` | 1 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Simple Solution with grep - E with | (OR) | detail explanation | simple-solution-with-grep-e-with-or-deta-nuov | I just found this Blog and Github repository with solutions to Leetcode problems.\nhttps://leet-codes.blogspot.com\nIt is very useful, and I just wanted to shar | pmistry_ | NORMAL | 2022-09-03T14:59:10.745206+00:00 | 2022-10-12T15:06:32.927809+00:00 | 684 | false | I just found this Blog and Github repository with solutions to Leetcode problems.\nhttps://leet-codes.blogspot.com\nIt is very useful, and I just wanted to share it with you.\nNote: You can bookmark it as a resource, and for another approaches\n<br>\n\n```\ngrep -E \'(^[0-9]{3}-|^\\([0-9]{3}\\) )[0-9]{3}-[0-9]{4}$\' fi... | 1 | 0 | [] | 0 |
valid-phone-numbers | [Regex] Runtime: 649 ms, faster than 5.46% of Go submissions | regex-runtime-649-ms-faster-than-546-of-cry2s | Complexity Analysis\n Time: O(N), where N is the number of lines within the file.txt.\n Space: O(1), constant number of variables used.\n\nsh\nfunction isValid( | d8dca782 | NORMAL | 2022-07-18T00:34:59.821033+00:00 | 2022-07-18T00:34:59.821068+00:00 | 384 | false | **Complexity Analysis**\n* Time: O(N), where N is the number of lines within the file.txt.\n* Space: O(1), constant number of variables used.\n\n```sh\nfunction isValid()\n{\n if [[ $1 =~ ^[0-9]{3}-[0-9]{3}-[0-9]{4}$ ]]; then\n return $(true)\n fi\n if [[ $1 =~ ^[(][0-9]{3}[)][[:space:]][0-9]{3}[-][0-9]{4}$ ]]; t... | 1 | 0 | [] | 0 |
valid-phone-numbers | One-Line Solution With Regex | one-line-solution-with-regex-by-jacdabro-uinm | Here is my solution:\n\n\n# Read from the file file.txt and output all valid phone numbers to stdout.\ngrep -E \'(^[0-9]{3}-|^\\([0-9]{3}\\) )[0-9]{3}-[0-9]{4}$ | jacdabro | NORMAL | 2022-07-05T15:05:39.688161+00:00 | 2022-07-05T16:13:24.440144+00:00 | 398 | false | Here is my solution:\n\n```\n# Read from the file file.txt and output all valid phone numbers to stdout.\ngrep -E \'(^[0-9]{3}-|^\\([0-9]{3}\\) )[0-9]{3}-[0-9]{4}$\' file.txt\n```\n\nor \n\n```\ngrep -P \'^(\\(\\d{3}\\) |\\d{3}-)\\d{3}-\\d{4}$\' file.txt\n``` | 1 | 0 | [] | 1 |
valid-phone-numbers | [BASH] - Easy One Liner | bash-easy-one-liner-by-tursunboyevjahong-do0u | https://leetcode.com/problems/valid-phone-numbers/discuss/843424/BASH-Easy-One-Liner\n\n\n1) grep -P \'^(\\d{3}-\\d{3}-\\d{4}|\\(\\d{3}\\) \\d{3}-\\d{4})$\' fil | TursunboyevJahongir | NORMAL | 2022-06-05T05:03:13.213097+00:00 | 2022-06-05T05:06:47.777270+00:00 | 847 | false | https://leetcode.com/problems/valid-phone-numbers/discuss/843424/BASH-Easy-One-Liner\n\n```\n1) grep -P \'^(\\d{3}-\\d{3}-\\d{4}|\\(\\d{3}\\) \\d{3}-\\d{4})$\' file.txt\n```\n\n```\n2) grep -Po \'^(\\(\\d{3}\\) |\\d{3}-)\\d{3}-\\d{4}$\' file.txt\n```\n\n```\n3) egrep \'^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3}\\)\\s[0-... | 1 | 0 | [] | 0 |
valid-phone-numbers | Grep [Runtime: 4 ms Memory Usage: 3.1 MB] | grep-runtime-4-ms-memory-usage-31-mb-by-3ock2 | \ngrep -Po \'^(\\(\\d{3}\\) |\\d{3}-)\\d{3}-\\d{4}$\' file.txt\n | ankitkumar734ac | NORMAL | 2022-01-23T13:46:28.992062+00:00 | 2022-01-23T13:46:28.992106+00:00 | 440 | false | ```\ngrep -Po \'^(\\(\\d{3}\\) |\\d{3}-)\\d{3}-\\d{4}$\' file.txt\n``` | 1 | 0 | [] | 0 |
valid-phone-numbers | 0ms solution. 100% faster! | 0ms-solution-100-faster-by-akshayabee19-dupq | grep -P "^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$" file.txt | akshayabee19 | NORMAL | 2021-08-19T17:05:41.471313+00:00 | 2021-08-19T17:05:41.471359+00:00 | 1,015 | false | ```grep -P "^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$" file.txt``` | 1 | 0 | [] | 0 |
valid-phone-numbers | egrep solution with cat | egrep-solution-with-cat-by-letrounet-uasi | \ncat file.txt | egrep "^((\\([0-9]{3}\\) )|([0-9]{3}-))[0-9]{3}-{0,1}[0-9]{4}$"\n\n | letrounet | NORMAL | 2021-07-20T00:53:07.820027+00:00 | 2021-07-20T00:53:07.820165+00:00 | 556 | false | ```\ncat file.txt | egrep "^((\\([0-9]{3}\\) )|([0-9]{3}-))[0-9]{3}-{0,1}[0-9]{4}$"\n```\n | 1 | 0 | [] | 1 |
valid-phone-numbers | Egrep Solution | egrep-solution-by-souradeepsaha-zkn5 | egrep "^([0-9]{3}-|\\([0-9]{3}\\) )[0-9]{3}-[0-9]{4}$" file.txt | souradeepsaha | NORMAL | 2021-06-11T05:42:35.727198+00:00 | 2021-06-11T05:42:35.727233+00:00 | 365 | false | ```egrep "^([0-9]{3}-|\\([0-9]{3}\\) )[0-9]{3}-[0-9]{4}$" file.txt``` | 1 | 1 | [] | 0 |
valid-phone-numbers | No grep solution (actually works) | no-grep-solution-actually-works-by-maker-7q7c | It took me a while, as some attempts "work on my machine" but not here lol. I\'m sure this can be simplified, but it took me a few hours to get this to work, so | makerbro | NORMAL | 2021-05-29T17:33:40.815417+00:00 | 2021-05-29T17:35:29.616511+00:00 | 626 | false | It took me a while, as some attempts "work on my machine" but not here lol. I\'m sure this can be simplified, but it took me a few hours to get this to work, so will stop here and see if anyone out there improves upon it. Using a slightly shorter regex, and even looking at SO examples, people seem to not care about a n... | 1 | 0 | [] | 1 |
valid-phone-numbers | Quick grep solution | quick-grep-solution-by-lozuwaucb-r9pb | Check the number lengths, the tokens and make sure it starts and ends appropiately. \n\n\ncat file.txt | grep -Ei "^(\\([0-9]{3}\\)\\s[0-9]{3}-[0-9]{4}$)|^([0-9 | lozuwaucb | NORMAL | 2021-04-18T01:18:47.468668+00:00 | 2021-04-18T01:18:47.468699+00:00 | 773 | false | Check the number lengths, the tokens and make sure it starts and ends appropiately. \n\n```\ncat file.txt | grep -Ei "^(\\([0-9]{3}\\)\\s[0-9]{3}-[0-9]{4}$)|^([0-9]{3}-[0-9]{3}-[0-9]{4}$)"\n``` | 1 | 1 | [] | 1 |
valid-phone-numbers | grep - P | grep-p-by-superroshan-22d7 | grep -P "^(\\(\\d{3}\\) |\\d{3}-)\\d{3}-\\d{4}$" file.txt | superroshan | NORMAL | 2021-01-21T05:18:45.605661+00:00 | 2021-01-21T05:19:44.072512+00:00 | 721 | false | ```grep -P "^(\\(\\d{3}\\) |\\d{3}-)\\d{3}-\\d{4}$" file.txt``` | 1 | 0 | [] | 0 |
valid-phone-numbers | Query related to input | query-related-to-input-by-_pii-cs5c | Can anyone tell me why this input is not valid \n(001)-345-0000\n\nthis is my bash one liner\ngrep -P \'^(\\(?\\d{3}|\\d{3})\\)?[\\s|-]\\d{3}-\\d{4}$\' file.txt | _pii_ | NORMAL | 2020-06-24T18:27:03.699601+00:00 | 2020-06-24T18:27:03.699645+00:00 | 355 | false | Can anyone tell me why this input is not valid \n```(001)-345-0000```\n\nthis is my bash one liner\n```grep -P \'^(\\(?\\d{3}|\\d{3})\\)?[\\s|-]\\d{3}-\\d{4}$\' file.txt```\n\nit also accepts the above number but gets an error saying it should not get accepted\n | 1 | 0 | [] | 1 |
valid-phone-numbers | grep -E | grep-e-by-gprx100-tjbr | ```\ncat file.txt | grep -E "^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\([0-9]{3}\) [0-9]{3}-[0-9]{4}$"\n\n | gprx100 | NORMAL | 2020-04-12T21:49:03.574670+00:00 | 2020-04-12T21:49:03.574709+00:00 | 592 | false | ```\ncat file.txt | grep -E "^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$"\n\n | 1 | 0 | [] | 0 |
valid-phone-numbers | mac bash or linux bash? | mac-bash-or-linux-bash-by-theosoft-ro89 | At first, I use this code:\n\ncat file.txt | grep -E "^(\\d{3}-|\\(\\d{3}\\)\\ )\\d{3}-\\d{4}$"\n\nIt works in my mac bash shell, but failed for the submission. | theosoft | NORMAL | 2020-03-27T13:45:38.099190+00:00 | 2020-03-27T13:45:38.099225+00:00 | 435 | false | At first, I use this code:\n```\ncat file.txt | grep -E "^(\\d{3}-|\\(\\d{3}\\)\\ )\\d{3}-\\d{4}$"\n```\nIt works in my mac bash shell, but failed for the submission.\nThen I changed my code to below:\n```\ncat file.txt | grep -E "^([0-9]{3}-|\\([0-9]{3}\\)\\ )[0-9]{3}-[0-9]{4}$"\n```\nThen passed... | 1 | 0 | [] | 1 |
valid-phone-numbers | why shebang and regular bash script not working? | why-shebang-and-regular-bash-script-not-jn15n | \n#!/bin/bash\ninput = \'file.txt\'\nre=\'([0-9][0-9][0-9]) [0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]\'\nre2=\'[0-9][0-9][0-9]-[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]\' | erjan | NORMAL | 2020-03-18T11:08:22.584823+00:00 | 2020-03-18T11:08:22.584858+00:00 | 225 | false | ```\n#!/bin/bash\ninput = \'file.txt\'\nre=\'([0-9][0-9][0-9]) [0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]\'\nre2=\'[0-9][0-9][0-9]-[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]\'\nwhile IFS read -r line;\ndo if [[$line = ~ $re || $line = ~re2 ]];\nthen echo $line\n``` | 1 | 1 | [] | 0 |
valid-phone-numbers | Solution without grep, awk, sed | solution-without-grep-awk-sed-by-kostmet-ncnp | \nwhile read LINE; do if [[ $LINE =~ (^\\([0-9]{3}\\)[[:blank:]][0-9]{3}-[0-9]{4}$)|(^[0-9]{3}-[0-9]{3}-[0-9]{4}$) ]]; then echo $LINE; fi; done < file.txt\n | kostmetallist | NORMAL | 2019-11-21T23:54:52.516598+00:00 | 2019-11-21T23:54:52.516642+00:00 | 920 | false | ```\nwhile read LINE; do if [[ $LINE =~ (^\\([0-9]{3}\\)[[:blank:]][0-9]{3}-[0-9]{4}$)|(^[0-9]{3}-[0-9]{3}-[0-9]{4}$) ]]; then echo $LINE; fi; done < file.txt\n``` | 1 | 0 | [] | 0 |
valid-phone-numbers | Trivial awk solution (probably been posted before) | trivial-awk-solution-probably-been-poste-y70g | \nawk -e \'/^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$|^[0-9]{3}-[0-9]{3}-[0-9]{4}$/{ print; }\' file.txt;\n | thebel | NORMAL | 2019-11-14T23:45:15.447901+00:00 | 2019-11-14T23:45:15.447952+00:00 | 321 | false | ```\nawk -e \'/^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$|^[0-9]{3}-[0-9]{3}-[0-9]{4}$/{ print; }\' file.txt;\n``` | 1 | 0 | [] | 3 |
valid-phone-numbers | Time = 0ms beats 100% with Memory = 3.1 MB, simple using Regex Grep | time-0ms-beats-100-with-memory-31-mb-sim-w8wg | \ncat file.txt | grep -E "(^[0-9]{3}-|^\\([0-9]{3}\\)\\s)[0-9]{3}-[0-9]{4}$"\n | terminator1296 | NORMAL | 2019-10-07T09:49:00.767231+00:00 | 2019-10-07T09:49:00.767278+00:00 | 828 | false | ```\ncat file.txt | grep -E "(^[0-9]{3}-|^\\([0-9]{3}\\)\\s)[0-9]{3}-[0-9]{4}$"\n``` | 1 | 0 | [] | 0 |
valid-phone-numbers | grep -P solution using conditional regex with explanation | grep-p-solution-using-conditional-regex-6tlnl | Conditional regular expressions are not always the most efficient solution. However, they can be really useful in reducing the length of the regular expression | akpircher | NORMAL | 2019-07-09T20:22:49.803994+00:00 | 2019-07-09T20:22:49.804032+00:00 | 537 | false | Conditional regular expressions are not always the most efficient solution. However, they _can_ be really useful in reducing the length of the regular expression by removing a long "or" statement with repeating elements. This is not one of those cases, but it\'s a fun solution. The downside is that they are harder to r... | 1 | 0 | [] | 0 |
valid-phone-numbers | egrep solution | egrep-solution-by-charliekenney23-ee73 | \ncat file.txt | egrep \'^(\\([[:digit:]]{3}\\) |[[:digit:]]{3}-)[[:digit:]]{3}-[[:digit:]]{4}$\'\n | charliekenney23 | NORMAL | 2019-06-25T05:38:48.434891+00:00 | 2019-06-25T05:38:48.434936+00:00 | 471 | false | ```\ncat file.txt | egrep \'^(\\([[:digit:]]{3}\\) |[[:digit:]]{3}-)[[:digit:]]{3}-[[:digit:]]{4}$\'\n``` | 1 | 0 | [] | 0 |
valid-phone-numbers | egrep solution | egrep-solution-by-codeywodey-7t05 | bash\ncat file.txt | egrep \'^(\\([0-9]{3}\\)\\s{1}|[0-9]{3}-)[0-9]{3}-[0-9]{4}$\'\n | codeywodey | NORMAL | 2019-04-14T01:18:40.511719+00:00 | 2019-04-14T01:18:40.511762+00:00 | 332 | false | ```bash\ncat file.txt | egrep \'^(\\([0-9]{3}\\)\\s{1}|[0-9]{3}-)[0-9]{3}-[0-9]{4}$\'\n``` | 1 | 0 | [] | 1 |
valid-phone-numbers | Fastest Awk Solution [8ms] | fastest-awk-solution-8ms-by-ganbatteimas-ehga | awk\nawk \'{if($0 ~ /^[0-9]{3}-[0-9]{3}-[0-9]{4}$/ || $0 ~ /^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$/){printf $0"\\n"}}\' file.txt\n\n\nSimply processes each line and | ganbatteimasu19 | NORMAL | 2019-03-25T00:50:51.405276+00:00 | 2019-03-25T00:50:51.405368+00:00 | 428 | false | ```awk\nawk \'{if($0 ~ /^[0-9]{3}-[0-9]{3}-[0-9]{4}$/ || $0 ~ /^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$/){printf $0"\\n"}}\' file.txt\n```\n\nSimply processes each line and checks if the entire record (default newline separated) has exactly the needed formats specified and prints each line that does. | 1 | 0 | [] | 0 |
valid-phone-numbers | Grep | grep-by-cantu_reinhard-0p20 | Never use solutions like these. Debugging this would be hell. grep "^\(\([0-9]\{3\}-\)\|\(([0-9]\{3\})\s\)\)[0-9]\{3\}-[0-9]\{4\}$" file.txt | cantu_reinhard | NORMAL | 2018-10-16T21:07:42.070900+00:00 | 2018-10-16T21:07:42.070993+00:00 | 386 | false | Never use solutions like these.
Debugging this would be hell.
```
grep "^\(\([0-9]\{3\}-\)\|\(([0-9]\{3\})\s\)\)[0-9]\{3\}-[0-9]\{4\}$" file.txt
``` | 1 | 0 | [] | 0 |
valid-phone-numbers | Wrong Output of Shell question "valid phone number" | wrong-output-of-shell-question-valid-pho-s0ur | For Shell Question "valid phone number", I submitted the below code: \n\n while read LINE\n do\n if [[ $LINE =~ "^\([0-9]{3}\) [0-9]{3}-[0-9]{4} | bati_goal | NORMAL | 2015-04-23T12:58:41+00:00 | 2015-04-23T12:58:41+00:00 | 595 | false | For Shell Question "valid phone number", I submitted the below code: \n\n while read LINE\n do\n if [[ $LINE =~ "^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$" ]] || [[ $LINE =~ "^[0-9]{3}-[0-9]{3}-[0-9]{4}$" ]]; then\n echo $LINE\n fi\n done < 'file.txt'\n\nFinally, Leetcode judge my code ... | 1 | 0 | [] | 1 |
valid-phone-numbers | whereis wrong with my pattern? ask for help | whereis-wrong-with-my-pattern-ask-for-he-2rh6 | my grep solution, the code is like:\n\ngrep "\\(?\\d{3}\\)?[- ]\\d{3}-\\d{4}" file.txt\n\nbut when it came across test case "123-456-7891", it didn't print out | lucasdove | NORMAL | 2017-05-21T12:30:41.550000+00:00 | 2017-05-21T12:30:41.550000+00:00 | 435 | false | my grep solution, the code is like:\n```\ngrep "\\(?\\d{3}\\)?[- ]\\d{3}-\\d{4}" file.txt\n```\nbut when it came across test case "123-456-7891", it didn't print out anything. could someone tell me why please?\nYet I put test case "123-456-7891" into a file, and open it with notepad++ on windows, using the same pattern... | 1 | 0 | [] | 1 |
valid-phone-numbers | 📞 Master Regex Filtering – Unlock the Power of Pattern Matching in Bash! | master-regex-filtering-unlock-the-power-ggz6v | IntuitionWhen processing text files, regular expressions allow us to find lines that match specific patterns. In this case, we're asked to identify phone number | loginov-kirill | NORMAL | 2025-04-07T22:12:54.357568+00:00 | 2025-04-07T22:12:54.357568+00:00 | 433 | false |
# Intuition
When processing text files, regular expressions allow us to find lines that match specific patterns. In this case, we're asked to identify phone numbers in two formats.
# Approach
- Use `gre... | 0 | 0 | ['Shell', 'Bash'] | 1 |
valid-phone-numbers | Kian Ilanluo | kian-ilanluo-by-kianilanluo-r3ry | IntuitionJust Think simpleApproach60 ms
Beats
84.45%Complexity
Time complexity:
60 ms
Beats
84.45%
Space complexity:
60 ms
Beats
84.45%
Code | kianilanluo | NORMAL | 2025-03-31T14:31:38.792726+00:00 | 2025-03-31T14:31:38.792726+00:00 | 2 | false | # Intuition
Just Think simple
# Approach
60 ms
Beats
84.45%
# Complexity
- Time complexity:
60 ms
Beats
84.45%
- Space complexity:
60 ms
Beats
84.45%
# Code
```bash []
# Read from the file file.txt and output all valid phone numbers to stdout.
grep -E '^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\([0-9]{3}\) [0-9]{3}-[0-9]{4}
``` ... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | shell | shell-by-rohan_shelke-9azd | IntuitionApproachComplexity
Time complexity:
Space complexity:
Code | Rohan_Shelke | NORMAL | 2025-03-30T05:27:00.605218+00:00 | 2025-03-30T05:27:00.605218+00:00 | 4 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
`... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | ❤️ Well explained what is the regex | well-explained-what-is-the-regex-by-muna-ksz9 | IntuitionApproachComplexity
Time complexity:
Space complexity:
CodeCode explaingrep Search for text in a file
-E Enable extended regex
^ Match start of line
$ | Munavar_PM | NORMAL | 2025-03-28T21:55:14.458720+00:00 | 2025-03-28T21:55:14.458720+00:00 | 4 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | One liner command | one-liner-command-by-niladridhar1-5jls | IntuitionSimple One liner command to get all the valid phone numbersCode | niladridhar1 | NORMAL | 2025-03-27T05:04:01.867928+00:00 | 2025-03-27T05:04:01.867928+00:00 | 5 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
Simple One liner command to get all the valid phone numbers
# Code
```bash []
# Read from the file file.txt and output all valid phone numbers to stdout.
cat file.txt | grep -E '^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\([0-9]{3}\) [0-9]{3}-[0-9]{4}
... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Solution using grep onliner extended regex | solution-using-grep-onliner-extended-reg-1y6y | Code | Nirzak | NORMAL | 2025-03-25T19:50:40.323345+00:00 | 2025-03-25T19:50:40.323345+00:00 | 4 | false | # Code
```bash []
# Read from the file file.txt and output all valid phone numbers to stdout.
grep -E "^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\\([0-9]{3}\\) [0-9]{3}-[0-9]{4}$" file.txt
``` | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | One-line solution with regex pattern | one-line-solution-with-regex-pattern-by-c2pdq | IntuitionApproach
Use regex as pattern for grep
Either start with any of these 2 patterns => ^(pattern1|pattern2)
pattern1: 3 digits and dash (e.g. 123-) => | Lesliee_2101 | NORMAL | 2025-03-21T13:40:09.202350+00:00 | 2025-03-21T13:41:27.490328+00:00 | 8 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
- Use regex as pattern for grep
- Either start with any of these 2 patterns => ^($$pattern1$$|$$pattern2$$)
$$pattern1$$: 3 digits and dash (e.g. 123-) => \d{3}-
$$patter... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Bash code 100% | bash-code-100-by-sunnat_dev_2011-ycdx | IntuitionApproachComplexity
Time complexity:
Space complexity:
Code | sunnat_dev_2011 | NORMAL | 2025-03-20T17:55:19.179327+00:00 | 2025-03-20T17:55:19.179327+00:00 | 9 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
`... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Simplest approach with explanation of regex and flags | simplest-approach-with-explanation-of-re-7s6v | IntuitionJust use grep command with -E flag for multiple regexApproachpass the regular expressions
[] : with - between represents range of selection
{} : repres | Abhijit_Dolai | NORMAL | 2025-03-19T20:07:21.790181+00:00 | 2025-03-19T20:07:21.790181+00:00 | 5 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
Just use grep command with -E flag for multiple regex
# Approach
<!-- Describe your approach to solving the problem. -->
pass the regular expressions
- [] : with - between represents range of selection
- {} : represents no. of times
- \ :... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Regex Phonenumbers | regex-phonenumbers-by-mrsander901-s7vo | IntuitionUse regex to filter phone numbers from a file.ApproachUse grep -E with two patterns: xxx-xxx-xxxx or (xxx) xxx-xxxx, anchored to match full lines.Code | MrSander901 | NORMAL | 2025-03-09T15:37:10.973276+00:00 | 2025-03-09T15:37:10.973276+00:00 | 9 | false | # Intuition
Use regex to filter phone numbers from a file.
# Approach
Use grep -E with two patterns: xxx-xxx-xxxx or (xxx) xxx-xxxx, anchored to match full lines.
# Code
```bash []
# Read from the file file.txt and output all valid phone numbers to stdout.
grep -E '^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\([0-9]{3}\) [0-9]{3}-... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | 193. Valid Phone Numbers Solution | 193-valid-phone-numbers-solution-by-muha-quch | IntuitionThe problem requires extracting phone numbers that match two specific formats:
(xxx) xxx-xxxx (where x is a digit)
xxx-xxx-xxxx
Given that the input is | Muhammad_Haris_Ahsan | NORMAL | 2025-03-06T02:42:41.210800+00:00 | 2025-03-06T02:42:41.210800+00:00 | 12 | false | # Intuition
The problem requires extracting phone numbers that match two specific formats:
1. `(xxx) xxx-xxxx` (where `x` is a digit)
2. `xxx-xxx-xxxx`
Given that the input is a text file where each line contains a single phone number, we can efficiently solve this using `grep`, a command-line tool that supports regu... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Concise Shell Script for Valid Phone Number Extraction using grep | concise-shell-script-for-valid-phone-num-dbev | IntuitionUse grep to filter lines in file.txt that match the specified phone number formats.ApproachUse grep -E with a regular expression to match either (xxx) | sharipovikromjon | NORMAL | 2025-03-01T01:50:04.140774+00:00 | 2025-03-01T01:50:04.140774+00:00 | 7 | false | # Intuition
Use **grep** to filter lines in **file.txt** that match the specified phone number formats.
# Approach
Use **grep -E** with a regular expression to match either **(xxx) xxx-xxxx** or **xxx-xxx-xxxx** formats. Anchor the regex to the start (**^**) and end (**$**) of the line for exact matches. Use **\s** for... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | 193. Valid Phone Numbers | 193-valid-phone-numbers-by-1hbxnllboo-odf8 | IntuitionUse regex to match valid phone numbers.ApproachUsing grep is enough to perform the regex match.Code | 1hBxNLlbOO | NORMAL | 2025-02-16T05:42:16.589322+00:00 | 2025-02-16T05:42:16.589322+00:00 | 9 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
Use regex to match valid phone numbers.
# Approach
<!-- Describe your approach to solving the problem. -->
Using `grep` is enough to perform the regex match.
# Code
```bash []
# Read from the file file.txt and output all valid phone numbe... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | No brainer, one liner | no-brainer-one-liner-by-nishant_sheoran-nhmr | Code | nishant_sheoran | NORMAL | 2025-02-14T12:44:15.040346+00:00 | 2025-02-14T12:44:15.040346+00:00 | 20 | false |
# Code
```bash []
grep -e "^[0-9]\{3\}\-[0-9]\{3\}\-[0-9]\{4\}$" -e "^([0-9]\{3\}) [0-9]\{3\}\-[0-9]\{4\}$" file.txt
``` | 0 | 0 | ['Shell', 'Bash'] | 0 |
valid-phone-numbers | Valid Phone Number using GREP | valid-phone-number-using-grep-by-samahaa-7w9u | IntuitionThe problem requires us to extract valid phone numbers from a file. A valid phone number follows one of two formats:(xxx) xxx-xxxx
xxx-xxx-xxxx
Given t | samahaabbas | NORMAL | 2025-02-09T11:49:03.900646+00:00 | 2025-02-09T11:49:03.900646+00:00 | 14 | false | # Intuition
The problem requires us to extract valid phone numbers from a file. A valid phone number follows one of two formats:
(xxx) xxx-xxxx
xxx-xxx-xxxx
Given that each line contains only one phone number, a line-by-line pattern match is the best approach.
# Approach
We use grep with extended regular expressions ... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Solution using grep+regex | solution-using-grepregex-by-u0ejuzk0o7-0ks8 | IntuitionThe problem asks us to identify valid phone numbers from a file. We are given specific formats that a valid phone number must follow:
(xxx) xxx-xxxx
xx | mehraj_hossain | NORMAL | 2025-02-09T02:35:01.509985+00:00 | 2025-02-09T02:35:01.509985+00:00 | 12 | false | # Intuition
The problem asks us to identify valid phone numbers from a file. We are given specific formats that a valid phone number must follow:
- `(xxx) xxx-xxxx`
- `xxx-xxx-xxxx`
Since both formats are well-structured, regular expressions (regex) can easily be used to capture and validate these patterns. We can us... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Valid Phone Numbers - Solution | valid-phone-numbers-solution-by-4auz20ig-cx9v | IntuitionThe problem requires extracting and printing phone numbers that match a specific format from a text file. Since each line contains a single phone numbe | 4AUZ20iGg6 | NORMAL | 2025-02-08T22:02:03.666894+00:00 | 2025-02-08T22:02:03.666894+00:00 | 7 | false | # Intuition
The problem requires extracting and printing phone numbers that match a specific format from a text file. Since each line contains a single phone number, we need a method to validate each line against the given formats:
1. ```(xxx) xxx-xxxx``` (Parentheses and space included)
1. ```xxx-xxx-xxxx``` (Only da... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Valid Phone Number | valid-phone-number-by-suman_tandan-6xjs | IntuitionApproachComplexity
Time complexity:
Space complexity:
Code | suman_tandan | NORMAL | 2025-02-05T05:30:25.108829+00:00 | 2025-02-05T05:30:25.108829+00:00 | 12 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
`... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Bash | Validate Phone Numbers Using grep | bash-validate-phone-numbers-using-grep-b-tyx5 | IntuitionWe need to extract valid phone numbers from file.txt.
A valid phone number follows one of these two formats:
xxx-xxx-xxxx
(xxx) xxx-xxxx
Since we are w | SamuelBrhaneAlemayohu | NORMAL | 2025-02-03T17:40:00.176296+00:00 | 2025-02-03T17:40:00.176296+00:00 | 32 | false | # Intuition
We need to extract valid phone numbers from `file.txt`.
A **valid phone number** follows one of these two formats:
1. `xxx-xxx-xxxx`
2. `(xxx) xxx-xxxx`
Since we are working in **Bash**, we can use `grep` with **regular expressions** to filter out invalid numbers.
# Approach
1. **Use `grep -E` (Extended... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | 193. Valid Phone Numbers | 193-valid-phone-numbers-by-g8xd0qpqty-s1zv | IntuitionApproachComplexity
Time complexity:
Space complexity:
Code | G8xd0QPqTy | NORMAL | 2025-01-10T07:21:01.725681+00:00 | 2025-01-10T07:21:01.725681+00:00 | 24 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
`... | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | POSIX Regexps | posix-regexps-by-spektrokalter-7u2l | null | spektrokalter | NORMAL | 2025-01-09T09:04:05.393848+00:00 | 2025-01-09T09:04:05.393848+00:00 | 14 | false | ```txt
cat file.txt |grep '^\(([0-9][0-9][0-9]) \|[0-9][0-9][0-9]-\)[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]
```
``` | 0 | 0 | ['Bash'] | 0 |
valid-phone-numbers | Sonakshi Tiwari | sonakshi-tiwari-by-sonakshigtiwari-ep9k | IntuitionApproachComplexity
Time complexity:
Space complexity:
Code | SONAKSHIGTIWARI | NORMAL | 2025-01-07T13:40:19.957434+00:00 | 2025-01-07T13:40:19.957434+00:00 | 7 | false | # Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
# Approach
<!-- Describe your approach to solving the problem. -->
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
# Code
`... | 0 | 0 | ['Bash'] | 0 |
binary-tree-zigzag-level-order-traversal | [c++] 5ms version: one queue and without reverse operation by using size of each level | c-5ms-version-one-queue-and-without-reve-8msj | \nAssuming after traversing the 1st level, nodes in queue are {9, 20, 8}, And we are going to traverse 2nd level, which is even line and should print value from | stevencooks | NORMAL | 2015-03-13T20:50:25+00:00 | 2018-10-19T14:45:07.857245+00:00 | 80,421 | false | \nAssuming after traversing the 1st level, nodes in queue are {9, 20, 8}, And we are going to traverse 2nd level, which is even line and should print value from right to left [8, 20, 9]. \n\nWe know there are 3 nodes in current queue, so the vector for this level in final result should be of size 3. \nThen, queue... | 503 | 8 | ['C++'] | 47 |
binary-tree-zigzag-level-order-traversal | My accepted JAVA solution | my-accepted-java-solution-by-awaylu-dnra | public class Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) \n {\n List<List<Integer>> sol = new ArrayList<>() | awaylu | NORMAL | 2014-09-17T06:17:28+00:00 | 2018-10-20T04:13:36.538433+00:00 | 145,645 | false | public class Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) \n {\n List<List<Integer>> sol = new ArrayList<>();\n travel(root, sol, 0);\n return sol;\n }\n \n private void travel(TreeNode curr, List<List<Integer>> sol, int ... | 476 | 7 | ['Java'] | 87 |
binary-tree-zigzag-level-order-traversal | JAVA Double Stack Solution | java-double-stack-solution-by-tjcd-uqg2 | public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n TreeNode c=root;\n List<List<Integer>> ans =new ArrayList<List<Integer>>();\n i | tjcd | NORMAL | 2015-12-26T14:24:44+00:00 | 2018-10-26T19:00:53.166043+00:00 | 30,507 | false | public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n TreeNode c=root;\n List<List<Integer>> ans =new ArrayList<List<Integer>>();\n if(c==null) return ans;\n Stack<TreeNode> s1=new Stack<TreeNode>();\n Stack<TreeNode> s2=new Stack<TreeNode>();\n s1.push(root);\n wh... | 336 | 4 | ['Java'] | 29 |
binary-tree-zigzag-level-order-traversal | [c++] Easy to understand, one approach to solve Zigzag & Level order traversal | c-easy-to-understand-one-approach-to-sol-0vig | This approch can be used to solve both level order traversal & zig zag traversal.\nIt\'s easy to start with the level order traversal. I hope the comments are c | mnumtw7 | NORMAL | 2018-09-26T15:49:46.925697+00:00 | 2019-08-17T23:52:56.083858+00:00 | 22,383 | false | This approch can be used to solve both level order traversal & zig zag traversal.\nIt\'s easy to start with the level order traversal. I hope the comments are clear.\n\n```\nvector<vector<int>> levelOrder(TreeNode* root) {\n if (!root) return {}; // return if root is null\n queue<TreeNode*> q;\n q.... | 241 | 3 | ['Tree', 'C'] | 19 |
binary-tree-zigzag-level-order-traversal | [Python] Clean BFS solution, explained | python-clean-bfs-solution-explained-by-d-eudl | In this problem we need to traverse binary tree level by level. When we see levels in binary tree, we need to think about bfs, because it is its logic: it first | dbabichev | NORMAL | 2020-07-22T10:47:30.078047+00:00 | 2020-07-22T10:47:30.078100+00:00 | 19,826 | false | In this problem we need to traverse binary tree level by level. When we see levels in binary tree, we need to think about **bfs**, because it is its logic: it first traverse all neighbors, before we go deeper. Here we also need to change direction on each level as well. So, algorithm is the following:\n\n1. We create *... | 237 | 5 | ['Breadth-First Search'] | 23 |
binary-tree-zigzag-level-order-traversal | A concise and easy understanding Java solution | a-concise-and-easy-understanding-java-so-p03m | public class Solution {\n public List> zigzagLevelOrder(TreeNode root) {\n List> res = new ArrayList<>();\n if(root == null) return res;\n\n | graceluli | NORMAL | 2015-11-11T23:29:46+00:00 | 2018-10-10T02:00:58.630632+00:00 | 36,436 | false | public class Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n List<List<Integer>> res = new ArrayList<>();\n if(root == null) return res;\n\n Queue<TreeNode> q = new LinkedList<>();\n q.add(root);\n boolean order = true;\n int size = 1;\n\n ... | 140 | 4 | [] | 23 |
binary-tree-zigzag-level-order-traversal | Python simple BFS | python-simple-bfs-by-fangkunjnsy-ynaq | Simple straightforward solution using flag to decide whether from left to right or from right to left\n\n class Solution(object):\n def zigzagLevelOrder(s | fangkunjnsy | NORMAL | 2015-09-23T04:24:02+00:00 | 2018-10-06T11:09:10.913549+00:00 | 30,587 | false | Simple straightforward solution using flag to decide whether from left to right or from right to left\n\n class Solution(object):\n def zigzagLevelOrder(self, root):\n """\n :type root: TreeNode\n :rtype: List[List[int]]\n """\n if not root: return []\n res, temp, stack, ... | 105 | 17 | [] | 31 |
binary-tree-zigzag-level-order-traversal | Clear iterative solution with deque, no reverse | clear-iterative-solution-with-deque-no-r-rtvl | for zig, pop_back, push_front, left then right, \n\n for zag, pop_front, push_back, right then left\n\n vector> zigzagLevelOrder(TreeNode* root) {\n v | qeatzy | NORMAL | 2015-08-09T08:33:26+00:00 | 2018-10-04T05:20:36.521379+00:00 | 16,834 | false | for zig, pop_back, push_front, left then right, \n\n for zag, pop_front, push_back, right then left\n\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n vector<vector<int>> res;\n if(!root) return res;\n std::deque<TreeNode*> deq;\n deq.push_back(root);\n int iszig=1;\n ... | 78 | 0 | [] | 6 |
binary-tree-zigzag-level-order-traversal | Four python solutions | four-python-solutions-by-nth-attempt-5r7m | Approach - 1\nUsing single ended queue and reverse. Although we are using deque we are utilizing only single ended queue functionality here.\npython\ndef zigzag | nth-attempt | NORMAL | 2020-07-23T02:20:54.455285+00:00 | 2021-02-28T16:28:49.579547+00:00 | 10,222 | false | #### Approach - 1\nUsing single ended queue and reverse. Although we are using `deque` we are utilizing only single ended queue functionality here.\n```python\ndef zigzagLevelOrder(self, root: TreeNode) -> List[List[int]]:\n\tif not root: return []\n\tqueue = collections.deque([root])\n\tres = []\n\teven_level = False\... | 74 | 0 | ['Queue', 'Python', 'Python3'] | 8 |
binary-tree-zigzag-level-order-traversal | 8-liner Python | 8-liner-python-by-tlhuang-w8ga | \nclass Solution(object):\n def zigzagLevelOrder(self, root):\n """\n :type root: TreeNode\n :rtype: List[List[int]]\n """\n | tlhuang | NORMAL | 2016-09-05T21:35:46.279000+00:00 | 2018-10-22T20:47:37.147954+00:00 | 10,575 | false | ```\nclass Solution(object):\n def zigzagLevelOrder(self, root):\n """\n :type root: TreeNode\n :rtype: List[List[int]]\n """\n if not root:\n return []\n res, level, direction = [], [root], 1\n while level:\n res.append([n.val for n in level][::... | 74 | 3 | [] | 11 |
binary-tree-zigzag-level-order-traversal | Two simple approaches : O(n) | two-simple-approaches-on-by-thisisakshat-7jyo | 1.)Recursion: After doing level order traversal using recursion, we simply reverse the vectors at alternate levels\n\nclass Solution {\npublic:\n void helper | thisisakshat | NORMAL | 2021-03-17T06:52:27.482277+00:00 | 2021-03-17T06:52:27.482313+00:00 | 7,761 | false | **1.)Recursion:** After doing level order traversal using recursion, we simply reverse the vectors at alternate levels\n```\nclass Solution {\npublic:\n void helper(TreeNode*root,vector<vector<int>>&res,int level)\n {\n if(!root) return; \n if(level>=res.size())\n res.push_back({});\n ... | 61 | 3 | ['Stack', 'Depth-First Search', 'Breadth-First Search', 'Recursion', 'Queue', 'C', 'C++'] | 8 |
binary-tree-zigzag-level-order-traversal | C++| Level Order Traversal | Beats 100% | BFS | c-level-order-traversal-beats-100-bfs-by-7lg3 | Intuition\n Describe your first thoughts on how to solve this problem. \nSo Do Simple Level order but alternately revrse the elemnts of level.\n- Either we can | Xahoor72 | NORMAL | 2023-02-17T17:44:03.017809+00:00 | 2023-02-17T17:44:03.017992+00:00 | 10,120 | false | # Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\nSo Do Simple Level order but alternately revrse the elemnts of level.\n- Either we can reverse the vector storing the elemnts f that level\n- Or we just insert from last index so that it will be in reverse order itself.(More Efficient)\n... | 50 | 3 | ['Tree', 'Depth-First Search', 'Breadth-First Search', 'Binary Tree', 'C++'] | 2 |
binary-tree-zigzag-level-order-traversal | 🚀Simplest Solution🚀||🔥Full Explanation||🔥C++🔥|| Python3 | simplest-solutionfull-explanationc-pytho-9e87 | Consider\uD83D\uDC4D\n\n Please Upvote If You Find It Helpful\n\n# Intuition\nIntuition of this problem is very simple.\nWe use the Level Ord | naman_ag | NORMAL | 2023-02-19T01:36:46.001514+00:00 | 2023-02-19T04:20:26.419287+00:00 | 7,726 | false | # Consider\uD83D\uDC4D\n```\n Please Upvote If You Find It Helpful\n```\n# Intuition\nIntuition of this problem is very simple.\nWe use the **Level Order Traversal** of Binary tree.\nFor the Zig Zag Movement we are using a variable `level` when it is **zero** we **move from Left to Right** and when ... | 41 | 2 | ['Tree', 'Breadth-First Search', 'Binary Tree', 'C++', 'Python3'] | 8 |
binary-tree-zigzag-level-order-traversal | My Java Solution Beats 98% | my-java-solution-beats-98-by-biedengle2-6haa | public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n List<List<Integer>> res = new ArrayList();\n travel(res, 0, root);\n return | biedengle2 | NORMAL | 2016-03-16T19:34:41+00:00 | 2018-10-01T03:38:10.590066+00:00 | 13,761 | false | public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n List<List<Integer>> res = new ArrayList();\n travel(res, 0, root);\n return res;\n }\n private void travel(List<List<Integer>> res, int level, TreeNode cur) {\n if (cur == null) return;\n if (res.size() <= level)... | 37 | 1 | ['Breadth-First Search', 'Java'] | 6 |
binary-tree-zigzag-level-order-traversal | Java iterative and recursive solutions. | java-iterative-and-recursive-solutions-b-ltjd | \n // bfs \n public List<List<Integer>> zigzagLevelOrder1(TreeNode root) {\n List<List<Integer>> ret = new ArrayList<>();\n Queue<TreeNo | oldcodingfarmer | NORMAL | 2016-05-07T07:56:46+00:00 | 2018-10-25T19:42:04.876984+00:00 | 9,754 | false | \n // bfs \n public List<List<Integer>> zigzagLevelOrder1(TreeNode root) {\n List<List<Integer>> ret = new ArrayList<>();\n Queue<TreeNode> queue = new LinkedList<>();\n queue.add(root);\n int l = 0;\n while (!queue.isEmpty()) {\n int size = queue.size();\n ... | 35 | 1 | ['Depth-First Search', 'Breadth-First Search', 'Java'] | 5 |
binary-tree-zigzag-level-order-traversal | JavaScript solution | javascript-solution-by-hongbo-miao-ymma | \nconst zigzagLevelOrder = (root) => {\n let res = [];\n\n const go = (node, lvl) => {\n if (node == null) return;\n if (res[lvl] == null) res[lvl] = [] | hongbo-miao | NORMAL | 2018-05-23T00:43:29.423454+00:00 | 2022-09-13T06:35:36.787337+00:00 | 4,412 | false | ```\nconst zigzagLevelOrder = (root) => {\n let res = [];\n\n const go = (node, lvl) => {\n if (node == null) return;\n if (res[lvl] == null) res[lvl] = [];\n\n if (lvl % 2 === 0) {\n res[lvl].push(node.val);\n } else {\n res[lvl].unshift(node.val);\n }\n\n go(node.left, lvl + 1);\n go(... | 34 | 0 | ['JavaScript'] | 5 |
binary-tree-zigzag-level-order-traversal | Day 50 || BFS || Easiest Beginner Friendly Sol | day-50-bfs-easiest-beginner-friendly-sol-52zs | Intuition of this Problem:\nThe problem asks us to perform a level-order traversal of a binary tree, but with a slight modification - we need to return the node | singhabhinash | NORMAL | 2023-02-19T01:48:48.184130+00:00 | 2023-02-19T02:07:58.427963+00:00 | 3,035 | false | # Intuition of this Problem:\nThe problem asks us to perform a level-order traversal of a binary tree, but with a slight modification - we need to return the nodes of each level in a zigzag order, starting from left to right and then right to left for the next level, and so on.\n\nThe intuition behind this problem is t... | 31 | 4 | ['Breadth-First Search', 'Binary Tree', 'C++', 'Java', 'Python3'] | 8 |
binary-tree-zigzag-level-order-traversal | Short and clear python code | short-and-clear-python-code-by-tusizi-9ndt | class Solution:\n # @param root, a tree node\n # @return a list of lists of integers\n def zigzagLevelOrder(self, root):\n queue = collections.d | tusizi | NORMAL | 2015-02-18T16:57:24+00:00 | 2018-10-04T21:27:48.302743+00:00 | 7,741 | false | class Solution:\n # @param root, a tree node\n # @return a list of lists of integers\n def zigzagLevelOrder(self, root):\n queue = collections.deque([root])\n res = []\n while queue:\n r = []\n for _ in range(len(queue)):\n q = queue.popleft()\n ... | 30 | 0 | ['Python'] | 4 |
binary-tree-zigzag-level-order-traversal | ✅ JAVA solution | java-solution-by-coding_menance-eipc | Code\nJAVA []\npublic class Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) \n {\n List<List<Integer>> sol = new ArrayList< | coding_menance | NORMAL | 2023-02-19T06:05:59.948690+00:00 | 2023-02-19T06:05:59.948734+00:00 | 3,120 | false | # Code\n``` JAVA []\npublic class Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) \n {\n List<List<Integer>> sol = new ArrayList<>();\n travel(root, sol, 0);\n return sol;\n }\n \n private void travel(TreeNode curr, List<List<Integer>> sol, int level)\n {\n... | 28 | 1 | ['Java'] | 2 |
binary-tree-zigzag-level-order-traversal | Two-stacks JavaScript solution | two-stacks-javascript-solution-by-jeanti-p94c | We can easily solve this problem using two stacks. The first stack s1 is used to traverse the current level of the tree, and the second stack s2 is used to trac | jeantimex | NORMAL | 2017-10-12T23:46:50.341000+00:00 | 2017-10-12T23:46:50.341000+00:00 | 1,926 | false | We can easily solve this problem using two stacks. The first stack `s1` is used to traverse the current level of the tree, and the second stack `s2` is used to track the nodes in the next level. Also, we need to have a `flag` to indicate the traversal direction has been flipped when the current level has been traversed... | 24 | 0 | [] | 3 |
binary-tree-zigzag-level-order-traversal | Javascript BFS | javascript-bfs-by-giddy-nw8v | Its a standard BFS with but the difference is we are keeping track of the depth at each level and that\'s determines if were adding to the front of the level a | giddy | NORMAL | 2020-04-15T04:41:16.523999+00:00 | 2020-04-15T04:41:16.524040+00:00 | 2,458 | false | Its a standard BFS with but the difference is we are keeping track of the depth at each level and that\'s determines if were adding to the front of the level array or the back of the level array. \n\n```\nvar zigzagLevelOrder = function(root) {\n if(!root) return [];\n let queue = [root];\n let output = [];\n let ... | 21 | 0 | ['Breadth-First Search', 'JavaScript'] | 2 |
binary-tree-zigzag-level-order-traversal | Python iterative BFS using deque | python-iterative-bfs-using-deque-by-work-awmm | With even or odd level, change the pop/append direction of the deque accordingly.\n\n```\nfrom collections import deque\nclass Solution:\n def zigzagLevelOrd | workcool | NORMAL | 2020-12-09T00:19:04.452944+00:00 | 2020-12-09T00:19:04.452982+00:00 | 1,547 | false | With even or odd level, change the pop/append direction of the deque accordingly.\n\n```\nfrom collections import deque\nclass Solution:\n def zigzagLevelOrder(self, root: TreeNode) -> List[List[int]]:\n if not root:\n return []\n \n dq = deque([root])\n res = []\n lvl =... | 20 | 0 | [] | 0 |
binary-tree-zigzag-level-order-traversal | Clean C++ solution using two stacks [1 ms] | clean-c-solution-using-two-stacks-1-ms-b-2yj1 | \nclass Solution {\npublic:\n \n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n \n stack<TreeNode*> LtoR, RtoL;\n int lvl = | devangarora | NORMAL | 2020-08-17T13:12:29.975485+00:00 | 2020-08-17T16:24:46.252853+00:00 | 1,874 | false | ```\nclass Solution {\npublic:\n \n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n \n stack<TreeNode*> LtoR, RtoL;\n int lvl = 1;\n \n vector<vector<int>> ans;\n \n if(!root) return ans;\n\n RtoL.push(root);\n\n while(!RtoL.empty() || !LtoR.... | 20 | 1 | ['C'] | 1 |
binary-tree-zigzag-level-order-traversal | Simple and clear python solution with explain | simple-and-clear-python-solution-with-ex-ug7s | I use a additional function addLevel to record the level number of nodes, then according to the level number, I can easily deal with the level order, see the co | qinzhou | NORMAL | 2015-03-22T12:48:51+00:00 | 2015-03-22T12:48:51+00:00 | 6,967 | false | I use a additional function addLevel to record the level number of nodes, then according to the level number, I can easily deal with the level order, see the code for details\n\n # Definition for a binary tree node\n # class TreeNode:\n # def __init__(self, x):\n # self.val = x\n # s... | 20 | 1 | ['Python'] | 4 |
binary-tree-zigzag-level-order-traversal | Video solution | Actual zig zag traversal | Complete intuition in detail | C++ | video-solution-actual-zig-zag-traversal-ey1iq | Video\nHey everyone i have created a video solution for this problem where we will actually traverse the binary tree in zig zag order , in the video i will be t | _code_concepts_ | NORMAL | 2024-08-06T11:02:22.656808+00:00 | 2024-08-06T13:32:35.089948+00:00 | 1,992 | false | # Video\nHey everyone i have created a video solution for this problem where we will actually traverse the binary tree in zig zag order , in the video i will be taking you through the complete thought process and intuition for the video, do watch till the end for complete explanantion.\n\nVideo link: https://youtu.be/1... | 19 | 0 | ['C++'] | 0 |
binary-tree-zigzag-level-order-traversal | Simple java solution, 0ms,100 Faster, using queue, bfs | simple-java-solution-0ms100-faster-using-7ttk | \n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode(int x) | kushguptacse | NORMAL | 2020-04-01T12:15:11.985697+00:00 | 2020-04-01T12:15:11.985728+00:00 | 2,098 | false | ```\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode(int x) { val = x; }\n * }\n */\nclass Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n List<List<Integer>> op = new LinkedList... | 19 | 0 | ['Breadth-First Search', 'Queue', 'Java'] | 0 |
binary-tree-zigzag-level-order-traversal | Java O(n) time O(log n) space | BFS | single Deque | 1ms | java-on-time-olog-n-space-bfs-single-deq-5mvu | The main idea is to \n1. Read from Front : left-to-right\n2. Write to Rear the left child followed by the right child\n3. Read from Rear : right-to-left\n4. Wri | black-panther | NORMAL | 2020-07-22T10:28:51.946473+00:00 | 2020-07-22T10:28:51.946505+00:00 | 2,317 | false | The main idea is to \n1. Read from Front : left-to-right\n2. Write to Rear the left child followed by the right child\n3. Read from Rear : right-to-left\n4. Write to Front the right child followed by the left child\n\nAs each item is removed from either end of the queue it is added to the result list\n | c-simple-code-using-2-stacks-on-by-vinee-lszq | \n vector<vector<int>> zigzagLevelOrder(TreeNode* root) { \n vector<vector<int>> ans;\n if(!root) return ans;\n stack<TreeNode*> dqL | vineet20 | NORMAL | 2021-10-25T10:20:53.388054+00:00 | 2021-10-25T10:20:53.388093+00:00 | 782 | false | ```\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) { \n vector<vector<int>> ans;\n if(!root) return ans;\n stack<TreeNode*> dqL;\n stack<TreeNode*> dqR;\n TreeNode* cur = root;\n dqL.push(cur);\n \n while(!dqL.empty() || !dqR.empty()){\n ... | 17 | 0 | [] | 3 |
binary-tree-zigzag-level-order-traversal | Easy Python solution || Level order traversal | easy-python-solution-level-order-travers-026l | \tdef zigzagLevelOrder(self, root: TreeNode) -> List[List[int]]:\n\t\t\tif not root:\n\t\t\t\treturn []\n\t\t\tlevel = 1\n\t\t\tres, curr, nxt = [], [root], [] | ItsMeSheersendu | NORMAL | 2021-07-18T20:20:32.609775+00:00 | 2021-07-18T20:20:32.609813+00:00 | 1,509 | false | \tdef zigzagLevelOrder(self, root: TreeNode) -> List[List[int]]:\n\t\t\tif not root:\n\t\t\t\treturn []\n\t\t\tlevel = 1\n\t\t\tres, curr, nxt = [], [root], [] \n\t\t\twhile curr:\n\t\t\t\tfor i in curr:\n\t\t\t\t\tif i.left:\n\t\t\t\t\t\tnxt.append(i.left)\n\t\t\t\t\tif i.right:\n\t\t\t\t\t\tnxt.append(i.right)\n\t\t\... | 15 | 1 | ['Python', 'Python3'] | 1 |
binary-tree-zigzag-level-order-traversal | 📌Easy C++ Solution | Just a small change in Level Order | easy-c-solution-just-a-small-change-in-l-hyav | Obervesion: We just need to reverse the alternate levels, rest is same as Level Ordering.\n\n\nclass Solution {\npublic:\n vector<vector<int>> zigzagLevelOrd | em_ashutosh | NORMAL | 2021-06-07T12:52:25.371851+00:00 | 2021-08-22T18:13:51.623391+00:00 | 1,858 | false | Obervesion: We just need to reverse the alternate levels, rest is same as Level Ordering.\n\n```\nclass Solution {\npublic:\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) \n {\n vector <vector<int>> v;\n if(!root) // if root is null return\n return v;\n queue <TreeNode*> q;... | 15 | 1 | ['C', 'C++'] | 1 |
binary-tree-zigzag-level-order-traversal | C++ BFS | c-bfs-by-rohitsaraf17-3sal | \nclass Solution {\npublic:\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n vector<vector<int>> ans;\n if(root == NULL)\n | rohitsaraf17 | NORMAL | 2020-01-05T23:06:39.882635+00:00 | 2020-01-05T23:06:39.882674+00:00 | 2,051 | false | ```\nclass Solution {\npublic:\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n vector<vector<int>> ans;\n if(root == NULL)\n return ans;\n queue<TreeNode*> info;\n info.push(root);\n bool flag = false;\n while(!info.empty()){\n int n = info.s... | 15 | 0 | ['Breadth-First Search', 'C'] | 6 |
binary-tree-zigzag-level-order-traversal | Python easy to understand deque solution | python-easy-to-understand-deque-solution-yvmx | \nclass Solution(object):\n def zigzagLevelOrder(self, root):\n deque = collections.deque()\n if root:\n deque.append(root)\n | oldcodingfarmer | NORMAL | 2015-07-14T19:43:28+00:00 | 2020-10-15T14:26:21.118133+00:00 | 3,808 | false | ```\nclass Solution(object):\n def zigzagLevelOrder(self, root):\n deque = collections.deque()\n if root:\n deque.append(root)\n res, level = [], 0\n while deque:\n l, size = [], len(deque)\n for _ in range(size): # process level by level\n ... | 15 | 0 | ['Breadth-First Search', 'Queue', 'Python'] | 3 |
binary-tree-zigzag-level-order-traversal | 🔥 [LeetCode The Hard Way] 🔥 Explained Line By Line | leetcode-the-hard-way-explained-line-by-o53hh | \uD83D\uDD34 Check out LeetCode The Hard Way for more solution explanations and tutorials. \n\uD83D\uDFE0 Check out our Discord Study Group for live discussion. | __wkw__ | NORMAL | 2023-02-19T03:04:14.912837+00:00 | 2023-02-19T03:04:14.912887+00:00 | 2,361 | false | \uD83D\uDD34 Check out [LeetCode The Hard Way](https://wingkwong.github.io/leetcode-the-hard-way/) for more solution explanations and tutorials. \n\uD83D\uDFE0 Check out our [Discord Study Group](https://discord.gg/Nqm4jJcyBf) for live discussion.\n\uD83D\uDFE2 Give a star on [Github Repository](https://github.com/wing... | 14 | 2 | ['Breadth-First Search', 'Python'] | 3 |
binary-tree-zigzag-level-order-traversal | My AC Java code | my-ac-java-code-by-lurklurk-0lwl | I use two stacks, one for processing current layer and one for storing nodes for the next layer. I also use a flag (order in your code) to indicate the directio | lurklurk | NORMAL | 2014-09-13T20:22:57+00:00 | 2014-09-13T20:22:57+00:00 | 5,057 | false | I use two stacks, one for processing current layer and one for storing nodes for the next layer. I also use a flag (order in your code) to indicate the direction. It is straightforward\n\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n List<List<Integer>> output = new ArrayList<List<Integer>>(... | 14 | 0 | [] | 2 |
binary-tree-zigzag-level-order-traversal | [recommend for beginners]clean C++ implementation with detailed explanation | recommend-for-beginnersclean-c-implement-1h4n | class Solution {\n public:\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n vector<vector<int>> result;\n if(!root) re | rainbowsecret | NORMAL | 2016-01-27T13:27:03+00:00 | 2018-10-26T02:13:25.211267+00:00 | 3,585 | false | class Solution {\n public:\n vector<vector<int>> zigzagLevelOrder(TreeNode* root) {\n vector<vector<int>> result;\n if(!root) return result;\n deque<TreeNode*> tree;\n tree.push_back(root);\n int flag=0;\n while(!tree.empty()){\n ... | 14 | 11 | [] | 6 |
binary-tree-zigzag-level-order-traversal | ✔️ 100% Fastest Swift Solution, time: O(n), space: O(n). | 100-fastest-swift-solution-time-on-space-4qjo | \n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * public var val: Int\n * public var left: TreeNode?\n * public var right | sergeyleschev | NORMAL | 2022-04-09T05:44:54.430598+00:00 | 2022-04-09T05:44:54.430645+00:00 | 486 | false | ```\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * public var val: Int\n * public var left: TreeNode?\n * public var right: TreeNode?\n * public init() { self.val = 0; self.left = nil; self.right = nil; }\n * public init(_ val: Int) { self.val = val; self.left = nil; sel... | 13 | 0 | ['Swift'] | 1 |
binary-tree-zigzag-level-order-traversal | 0ms beats 100%. Easy to understand recursive solution. | 0ms-beats-100-easy-to-understand-recursi-bq6s | \n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode(int x) | gullible_frog | NORMAL | 2019-11-25T03:39:55.012508+00:00 | 2019-11-25T03:41:09.525837+00:00 | 1,356 | false | ```\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode(int x) { val = x; }\n * }\n */\nclass Solution {\n public List<List<Integer>> zigzagLevelOrder(TreeNode root) {\n \n List<List<Integer>> res = new... | 13 | 0 | ['Recursion', 'Java'] | 3 |
binary-tree-zigzag-level-order-traversal | C++ ✅ || Beats 100%💯 || Fast Solution🔥|| Simple Code🚀 | c-beats-100-fast-solution-simple-code-by-z867 | 🌟 Intuition"Let's go zigzag through the tree, level by level!"
This problem is like navigating a forest, but with a twist! Instead of moving straight, we need t | yashm01 | NORMAL | 2024-12-27T08:11:46.812160+00:00 | 2024-12-27T08:11:46.812160+00:00 | 1,723 | false | 
# 🌟 Intuition
*"Let's go zigzag through the tree, level by level!"*
This problem is like navigating a forest, but with a twist! Instead of moving straight, we need to alternate ... | 12 | 0 | ['Tree', 'Breadth-First Search', 'Binary Tree', 'C++'] | 0 |
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