Hard · Backtracking

N-Queens

Given an integer n, place n queens on an n×n board so that no two share a row, column or diagonal, and return the lexicographically smallest such placement as the 0-based queen column of each row together with true, or null and false when no placement exists (n = 2 or 3).

Examples

Example 1

n = 4

Output: [1, 3, 0, 2]

Example 2

n = 6

Output: [1, 3, 5, 0, 2, 4]

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