【POJ 2676】 Sudoku

【题目链接】

            http://poj.org/problem?id=2676

【算法】

          深度优先搜索

【代码】

             

#include <algorithm>  
#include <bitset>  
#include <cctype>  
#include <cerrno>  
#include <clocale>  
#include <cmath>  
#include <complex>  
#include <cstdio>  
#include <cstdlib>  
#include <cstring>  
#include <ctime>  
#include <deque>  
#include <exception>  
#include <fstream>  
#include <functional>  
#include <limits>  
#include <list>  
#include <map>  
#include <iomanip>  
#include <ios>  
#include <iosfwd>  
#include <iostream>  
#include <istream>  
#include <ostream>  
#include <queue>  
#include <set>  
#include <sstream>  
#include <stdexcept>  
#include <streambuf>  
#include <string>  
#include <utility>  
#include <vector>  
#include <cwchar>  
#include <cwctype>  
#include <stack>  
#include <limits.h> 
using namespace std;

struct info
{
        int x,y;
} pos[110];

int i,j,len,T;
char mp[10][10];
bool row[10][10],col[10][10],grid[10][10];
bool solved;

inline int getpos(int x,int y)
{
        return (x - 1) / 3 * 3 + (y - 1) / 3 + 1;        
}
inline void dfs(int dep)
{
        int i;
        if (dep > len)
        {
                solved = true;
                return;        
        }    
        for (i = 1; i <= 9; i++)
        {
                if (!row[pos[dep].x][i] && !col[pos[dep].y][i] && !grid[getpos(pos[dep].x,pos[dep].y)][i])
                {
                        mp[pos[dep].x][pos[dep].y] = i + '0';
                        row[pos[dep].x][i] = true;
                        col[pos[dep].y][i] = true;
                        grid[getpos(pos[dep].x,pos[dep].y)][i] = true;
                        dfs(dep+1);
                        if (solved) return;
                        row[pos[dep].x][i] = false;
                        col[pos[dep].y][i] = false;
                        grid[getpos(pos[dep].x,pos[dep].y)][i] = false;
                }
        }
}

int main() 
{
        
        scanf("%d",&T);
        getchar();
        while (T--)
        {
                solved = false;
                memset(row,false,sizeof(row));
                memset(col,false,sizeof(col));
                memset(grid,false,sizeof(grid));
                len = 0;
                for (i = 1; i <= 9; i++)
                {
                        for (j = 1; j <= 9; j++)
                        {
                                mp[i][j] = getchar();    
                                if (mp[i][j] == '0') pos[++len] = (info){i,j};
                                else 
                                {
                                        row[i][mp[i][j]-'0'] = true;
                                        col[j][mp[i][j]-'0'] = true;    
                                        grid[getpos(i,j)][mp[i][j]-'0'] = true;    
                                }                                    
                        }    
                        getchar();
                }    
                dfs(1);
                for (i = 1; i <= 9; i++)
                {
                        for (j = 1; j <= 9; j++)
                        {
                                printf("%c",mp[i][j]);
                        }
                        printf("
");
                }
        }
        
        return 0;
    
}