LeetCode 37 Sudoku Solver (C,C++,Java,Python)

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Problem:

Write a program to solve a Sudoku puzzle by filling the empty cells.

Empty cells are indicated by the character '.'.

You may assume that there will be only one unique solution.

A sudoku puzzle...

...and its solution numbers marked in red.

Solution:

采用笨拙的DFS的办法，判断填入的数字是否合法，可以通过三个规则事先过滤掉不合法的数字，然后试试剩余的是否有合法的数字

题目大意：

填数独游戏。。。。。。

Java源代码（300ms）：

public class Solution {    public void solveSudoku(char[][] board) {        SudoKu(board,0,0);    }    private boolean SudoKu(char[][] board,int i,int j){        if(i==8 && j==9)return true;        if(j==9){            i++;j=0;        }        if(board[i][j]!='.'){            if(SudoKu(board,i,j+1))return true;        }else{            int[] map=getValidNum(board,i,j);            for(int k=1;k<10;k++){                if(map[k]==0){                    board[i][j]=(char)(k+'0');                    if(SudoKu(board,i,j+1))return true;                    board[i][j]='.';                }            }        }        return false;    }    private int[] getValidNum(char[][] board,int i,int j){        int[] map=new int[10];        for(int k=0;k<9;k++){            if(board[i][k]!='.')map[board[i][k]-'0']=1;            if(board[k][j]!='.')map[board[k][j]-'0']=1;        }        for(int k=3*(i/3);k<3*(i/3)+3;k++){            for(int l=3*(j/3);l<3*(j/3)+3;l++){                if(board[k][l]!='.')map[board[k][l]-'0']=1;            }        }        return map;    }}

C语言源代码（12ms）：

int* getValidNum(char** board,int i,int j){    int k,l;    int* map = (int*)malloc(sizeof(int)*10);    memset(map,0,sizeof(int)*10);    for(k=0;k<9;k++){        if(board[i][k]!='.') map[board[i][k]-'0']=1;    }    for(k=0;k<9;k++){        if(board[k][j]!='.') map[board[k][j]-'0']=1;    }    for(k=3*(i/3);k<3*(i/3)+3;k++){        for(l=3*(j/3);l<3*(j/3)+3;l++){            if(board[k][l]!='.') map[board[k][l]-'0']=1;        }    }    return map;}bool SudoKu(char** board,int i,int j){    int k;    if(i==8 && j==9)return true;    if(j==9){        i++;        j=0;    }    if(board[i][j]!='.'){        if(SudoKu(board,i,j+1))return true;    }else{        int* map=getValidNum(board,i,j);        for(k=1;k<10;k++){            if(map[k]==0){                board[i][j]=k+'0';                if(SudoKu(board,i,j+1))return true;                board[i][j]='.';            }        }        free(map);    }    return false;} void solveSudoku(char** board, int boardRowSize, int boardColSize) {    SudoKu(board,0,0);}

C++源代码（24ms）：

class Solution {public:    void solveSudoku(vector<vector<char>>& board) {        SudoKu(board,0,0);    }private:    bool SudoKu(vector<vector<char>>& board,int i,int j){        if(i==8 && j==9)return true;        if(j==9){            i++;j=0;        }        if(board[i][j]!='.'){            if(SudoKu(board,i,j+1))return true;        }else{            int* map=getValidNum(board,i,j);            for(int k=1;k<10;k++){                if(map[k]==0){                    board[i][j]=k+'0';                    if(SudoKu(board,i,j+1))return true;                    board[i][j]='.';                }            }        }        return false;    }    int* getValidNum(vector<vector<char>>& board,int i,int j){        int* map=(int*)malloc(sizeof(int)*10);        memset(map,0,sizeof(int)*10);        for(int k=0;k<9;k++){            if(board[i][k]!='.')map[board[i][k]-'0']=1;            if(board[k][j]!='.')map[board[k][j]-'0']=1;        }        for(int k=3*(i/3);k<3*(i/3)+3;k++){            for(int l=3*(j/3);l<3*(j/3)+3;l++){                if(board[k][l]!='.')map[board[k][l]-'0']=1;            }        }        return map;    }};

Python源代码（636ms）：

class Solution:    # @param {character[][]} board    # @return {void} Do not return anything, modify board in-place instead.    def solveSudoku(self, board):        self.SudoKu(board,0,0)    def SudoKu(self,board,i,j):        if i==8 and j==9:return True        if j==9:i+=1;j=0        if board[i][j]!='.':            if self.SudoKu(board,i,j+1):return True        else:            map=self.getValidNum(board,i,j)            for k in range(1,10):                if map[k]==0:                    board[i][j]=chr(k+ord('0'))                    if self.SudoKu(board,i,j+1):return True                    board[i][j]='.'        return False    def getValidNum(self,board,i,j):        map=[0 for k in range(10)]        for k in range(9):            if board[i][k]!='.':map[ord(board[i][k])-ord('0')]=1            if board[k][j]!='.':map[ord(board[k][j])-ord('0')]=1        for k in range(3*(i/3),3*(i/3)+3):            for l in range(3*(j/3),3*(j/3)+3):                if board[k][l]!='.':map[ord(board[k][l])-ord('0')]=1        return map

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