| { | |
| "name": "costas_array_n8__v6_nh", | |
| "problem_type": "costas_array", | |
| "params": { | |
| "n": 8 | |
| }, | |
| "prompt": "Find a Costas array of order 8: place 8 marks on an 8x8 grid, one per row and one per column, such that all 8*(7)/2 displacement vectors (dr, dc) between pairs of marks (with dc > 0) are pairwise distinct.\n\nReturn x as a list of 8 integers in 0..7, where x[c] is the row of the mark in column c (permutation), or state \"UNSATISFIABLE\" if no such array exists.", | |
| "satisfiable": true, | |
| "solution": { | |
| "x": [ | |
| 4, | |
| 7, | |
| 3, | |
| 2, | |
| 0, | |
| 5, | |
| 6, | |
| 1 | |
| ] | |
| }, | |
| "difficulty": { | |
| "solve_time_ms": 880.3, | |
| "search_space": 40320, | |
| "num_variables": 8, | |
| "num_constraints": 9, | |
| "num_edges": -1, | |
| "backend": "pycsp", | |
| "solve_tier": "medium", | |
| "solve_pct_global": 56.95, | |
| "solve_pct_type": 27.78 | |
| }, | |
| "partial_assignment": null | |
| } | |