Input: board =
[["8","3",".",".","7",".",".",".","."]
,["6",".",".","1","9","5",".",".","."]
,[".","9","8",".",".",".",".","6","."]
,["8",".",".",".","6",".",".",".","3"]
,["4",".",".","8",".","3",".",".","1"]
,["7",".",".",".","2",".",".",".","6"]
,[".","6",".",".",".",".","2","8","."]
,[".",".",".","4","1","9",".",".","5"]
,[".",".",".",".","8",".",".","7","9"]]
Output: false
Explanation: Same as Example 1, except with the5 in the top left corner being modified to8. Since there are two 8's in the top left 3x3 sub-box, it is invalid.
Constraints:
board.length == 9
board[i].length == 9
board[i][j] is a digit 1-9 or '.'.
Time: O(1)
Space: O(1)
/** * @param{character[][]} board * @return{boolean} */constpoints= [ [0,0], [0,3], [0,6], [3,0], [3,3], [3,6], [6,0], [6,3], [6,6],];constset=newSet();varisValidSudoku=function(board) {let flag =true;for (let i =0; i <9; i++) {set.clear(); flag =checkRow(i, board);if (!flag) returnfalse;set.clear(); flag =checkColumn(i, board);if (!flag) returnfalse; }for (const [row,col] of points) {set.clear(); flag =check(row, col, board);if (!flag) returnfalse; }return flag;};functioncheckRow(col, board) {for (let i =0; i <9; i++) {constcurr= board[i][col];if (curr ==='.') continue;if (set.has(curr)) returnfalse;set.add(curr); }returntrue;}functioncheckColumn(row, board) {for (let i =0; i <9; i++) {constcurr= board[row][i];if (curr ==='.') continue;if (set.has(curr)) returnfalse;set.add(curr); }returntrue;}functioncheck(row, col, board) {for (let i =0; i <3; i++) {for (let j =0; j <3; j++) {constcurr= board[row + i][col + j];if (curr ==='.') continue;if (set.has(curr))returnfalse;set.add(curr); } }returntrue;}