poj2676

搜索

#include <iostream>

#include <cstdlib>

#include <cstring>

#include <cstdio>

using namespace std;



#define maxn 15



int n;

int map[maxn][maxn];

bool visr[maxn][maxn], visc[maxn][maxn], visb[maxn][maxn][maxn];

bool found;



void make(int x, int y, int a, bool v)

{

    visr[x][a] = v;

    visc[y][a] = v;

    visb[x / 3][y / 3][a] = v;

}



void input()

{

    char st[maxn];

    for (int i = 0; i < 9; i++)

    {

        scanf("%s", st);

        for (int j = 0; j < 9; j++)

        {

            map[i][j] = st[j] - '0';

            make(i, j, map[i][j], true);

        }

    }

}



bool ok(int x, int y, int a)

{

    return !visr[x][a] && !visc[y][a] && !visb[x / 3][y / 3][a];

}



void print()

{

    for (int i = 0; i < 9; i++)

    {

        for (int j = 0; j < 9; j++)

            printf("%d", map[i][j]);

        putchar('\n');

    }

}



void dfs(int pos)

{

    if (found)

        return;

    if (pos == 9 * 9)

    {

        found = true;

        print();

        return;

    }

    int x = pos / 9;

    int y = pos % 9;

    if (map[x][y])

    {

        dfs(pos + 1);

        return;

    }

    for (int i = 1; i <= 9; i++)

        if (ok(x, y, i))

        {

            make(x, y, i, true);

            map[x][y] = i;

            dfs(pos + 1);

            map[x][y] = 0;

            make(x, y, i, false);

        }

}



int main()

{

    //freopen("t.txt", "r", stdin);

    int t;

    scanf("%d", &t);

    while (t--)

    {

        memset(visr, 0, sizeof(visr));

        memset(visc, 0, sizeof(visc));

        memset(visb, 0, sizeof(visb));

        input();

        found = false;

        dfs(0);

    }

    return 0;

}

View Code