| { | |
| "name": "langford_n6__v8", | |
| "problem_type": "langford", | |
| "params": { | |
| "n": 6 | |
| }, | |
| "prompt": "Construct a Langford sequence L(2,6): a sequence of length 12 containing exactly 2 copies of each integer from 1 to 6, such that the two occurrences of each value v are exactly v+1 positions apart (so copies of 1 are 1 position apart, copies of 2 are 2 positions apart, etc.). Example: L(2,3) has solution [2, 3, 1, 2, 1, 3].\n\nReturn seq as a list of 12 integers in 1..6, or state \"UNSATISFIABLE\" if no such sequence exists.", | |
| "satisfiable": false, | |
| "solution": null, | |
| "difficulty": { | |
| "solve_time_ms": 1434.5, | |
| "search_space": 479001600, | |
| "num_variables": 12, | |
| "num_constraints": 83, | |
| "num_edges": -1, | |
| "backend": "pycsp", | |
| "solve_tier": "hard", | |
| "solve_pct_global": 85.53, | |
| "solve_pct_type": 18.75 | |
| }, | |
| "partial_assignment": null | |
| } | |