time O(4^16)
space O(16)
1
4
4
1
2
3
3
1
Start solving the Sudoku board using Backtracking.
Pseudocode
Pseudocode
1function solveSudoku(board, N):
2 for r from 0 to N-1:
3 for c from 0 to N-1:
4 if board[r][c] == empty:
5 for num from 1 to N:
6 if isValid(board, r, c, num):
7 board[r][c] = num
8 if solveSudoku(board): return true
9 board[r][c] = empty
10 return false
11 return true