instances/costas_array_n5__v3_h.json

{
  "name": "costas_array_n5__v3_h",
  "problem_type": "costas_array",
  "params": {
    "n": 5
  },
  "prompt": "Find a Costas array of order 5: place 5 marks on an 5x5 grid, one per row and one per column, such that all 5*(4)/2 displacement vectors (dr, dc) between pairs of marks (with dc > 0) are pairwise distinct.\n\nReturn x as a list of 5 integers in 0..4, where x[c] is the row of the mark in column c (permutation), or state \"UNSATISFIABLE\" if no such array exists.\n\nPartial assignment (fixed values that must be respected):\n- x[2]=3\nReturn a complete solution consistent with these fixed assignments.",
  "satisfiable": true,
  "solution": {
    "x": [
      0,
      2,
      3,
      1,
      4
    ]
  },
  "difficulty": {
    "solve_time_ms": 842.2,
    "search_space": 120,
    "num_variables": 5,
    "num_constraints": 6,
    "num_edges": -1,
    "backend": "pycsp",
    "solve_tier": "medium",
    "solve_pct_global": 55.45,
    "solve_pct_type": 5.56
  },
  "partial_assignment": {
    "x": {
      "2": 3
    }
  }
}