ZOJ 2859 Matrix Searching

题目链接：http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=1859

题目：给出一个矩阵，求出指定子矩阵中的最小元素。

我用的不是正规解法，纯属水过去的……这个是留着自己看的，大家就不要学了。

#include <cstdio>
#include <cstring>

const int MAXN = 300 + 10;

int map[MAXN][MAXN];
int Mat[MAXN][MAXN];

int n;
int INF = 2147483645;

int min( int a, int b )
{
    return a < b ? a : b;
}

int Findmin( int x1, int y1, int x2, int y2 )
{
    if ( x1 == 1 && y1 == 1 ) return Mat[x2][y2];
    if ( Mat[x2][y2] != Mat[x1][y2] && Mat[x2][y2] != Mat[x2][y1] ) return Mat[x2][y2];

    int mmin = INF;
    for ( int i = x1; i <= x2; i++ )
       for ( int j = y1; j <= y2; j++ )
          if ( map[i][j] < mmin ) mmin = map[i][j];

    return mmin;
}

int main()
{
    int T;
    scanf( "%d", &T );
    while ( T-- )
    {
        scanf( "%d", &n );

        for ( int i = 1; i <= n; i++ )
        {
            for ( int j = 1; j <= n; j++ )
            {
                scanf( "%d", &map[i][j] );
                if ( i == 1 && j == 1 )
                    Mat[i][j] = map[i][j];
                else if ( i != 1 && j == 1 )
                    Mat[i][j] = min( map[i][j], Mat[i - 1][j] );
                else if ( i == 1 && j != 1 )
                    Mat[i][j] = min( map[i][j], Mat[i][j - 1] );
                else Mat[i][j] = min( map[i][j], min(Mat[i - 1][j], Mat[i][j - 1]) );
            }
        }

        int m;
        scanf( "%d", &m );
        while ( m-- )
        {
            int a, b, c, d;
            scanf("%d%d%d%d", &a, &b, &c, &d);
            printf("%d\n", Findmin( a, b, c, d ) );
        }
    }
    return 0;
}