Check Corners HDU - 2888

原题链接
考察:RMQ
思路:
  二维模板题

Code

#include <iostream>
#include <cstring>
#include <cmath>
using namespace std;
const int N = 310,M = 10;
int m, n,w[N][N],Q,f[N][M][N][M];
void init()
{
    for (int x = 0; x < M;x++)
        for (int y = 0; y < M;y++)
            for (int i = 1; i + (1 << x) - 1 <= m;i++)
                for (int j = 1; j + (1 << y) - 1 <= n;j++)
                {
                    f[i][x][j][y] = 0;
                    if(!x&&!y)
                        f[i][x][j][y] = w[i][j];
                    else if(!x)
                        f[i][x][j][y] = max(f[i][x][j][y - 1], f[i][x][j + (1 << y - 1)][y - 1]);
                    else if(!y)
                        f[i][x][j][y] = max(f[i][x - 1][j][y], f[i + (1 << x - 1)][x-1][j][y]);
                    else
                        f[i][x][j][y] = max(f[i][x - 1][j][y - 1], f[i + (1 << x - 1)][x - 1][j][y - 1]),
                        f[i][x][j][y] = max(f[i][x][j][y], f[i][x - 1][j + (1 << y - 1)][y - 1]),
                        f[i][x][j][y] = max(f[i][x][j][y], f[i + (1 << x - 1)][x - 1][j + (1 << y - 1)][y - 1]);
                }
}
bool check(int a,int b,int c,int d,int res)
{
    if(w[a][b]==res)
        return 1;
    if(w[a][d]==res)
        return 1;
    if(w[c][b]==res)
        return 1;
    if(w[c][d]==res)
        return 1;
    return 0;
}
int main()
{
    while(scanf("%d%d",&m,&n)!=EOF)
    {
        for (int i = 1; i <= m;i++)
            for (int j = 1; j <= n;j++)
                scanf("%d", &w[i][j]);
        init();
        scanf("%d", &Q);
        while(Q--)
        {
            int a, b, c, d;
            scanf("%d%d%d%d", &a, &b, &c, &d);
            int ak = log(c - a + 1) / log(2), bk = log(d - b + 1) / log(2);
            int ans = max(f[a][ak][b][bk], f[a][ak][d - (1 << bk) + 1][bk]);
            ans = max(f[c - (1 << ak) + 1][ak][b][bk], ans);
            ans = max(f[c - (1 << ak) + 1][ak][d - (1 << bk) + 1][bk],ans);
            printf("%d ", ans);
            if(check(a,b,c,d,ans))
                printf("yes\n");
            else
                printf("no\n");
        }
    }
    return 0;
}