Leetcode 36.Valid Sudoku (effective Sudoku) thinking and method of solving problems

Valid Sudoku

Determine if a Sudoku is valid, according To:sudoku puzzles-the Rules.

The Sudoku board could be partially filled, where empty cells is filled with the character '.

A partially filled sudoku which is valid.

Note:

A Valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

Ideas: The topic is very simple, the main rule of understanding, Sudoku game has not played, do not know what the rules, I think any 9 squares 1-9 of the number is at most 1, who knows the rule is a specific nine lattice 1-9 of the number of the maximum is 1, other not considered. The code is verbose, but the idea is clear, as follows:

public class Solution {//static variable map<character,integer> Map = new hashmap<character,integer> ();            public boolean Isvalidsudoku (char[][] board) {//judgment per line for (int i = 0; i < board.length; i++) { Initmap ();//need to initialize for (int j = 0; J < Board[0].length, J + +) for each time {//is the number if (board[                        I][J] >= ' 0 ' && board[i][j] <= ' 9 ') {if (Map.get (board[i][j]) > 0) {//Description repeat Number                    return false;                    }else{Map.put (board[i][j],1); }}else if (board[i][j]! = '. ')        {//appear spaces and characters other than 0-9 return false;//direct return false}} }//Judge each column for (int i = 0; i < board[0].length; i++) {initmap ();//Initialize for (int j =) each time. 0; J < Board.length;    J + +) {//is the number if (Board[j][i] >= ' 0 ' && board[j][i] <= ' 9 ') {                if (Map.get (Board[j][i]) > 0) {//Description repeat number return false;                    }else{Map.put (board[j][i],1); }}else if (board[j][i]! = '. ')        {//appear spaces and characters other than 0-9 return false;//direct return false}} }//Judge nine for (int i = 0; i < board.length-2; i = i+3) {//Line {for (int j = 0; J < Board[0].le Ngth-2; j=j+3) {initmap ();//Initialize for (int m = i, M < i + 3;m++) {for (int n = j; n < j+3;                            n++) {//is the number if (Board[m][n] >= ' 0 ' && board[m][n] <= ' 9 ') {                            if (Map.get (Board[m][n]) > 0) {//Description repeat number return false;                            }else{Map.put (board[m][n],1); }}else if (board[m][n]! = '. ') {//appearsA space and a character other than 0-9 return false;//directly returns false}}    }}} return true;        }//Initialize map assigns a value of 0 private void Initmap () {for (char i = ' 0 '; I <= ' 9 '; i++) {map.put (i,0) to each key; }    }}

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Leetcode 36.Valid Sudoku (effective Sudoku) thinking and method of solving problems