1.题目链接。题目大意，给定一个矩阵，然后Q组询问，询问是(x,y,x1,y1).问以这两个点组成的子矩阵里面的最大值是不是在四个角上。
2.RMQ寻找最大值，然后判断一下是不是在角上即可。但是注意一下这里的内存已经是很有限了，所以需要严格的注意数组大小很容易MLE。
#include<iostream>
#include <string.h>
#include <iostream>
#include <algorithm>
#include<stdio.h>
#include<cstdio>
#pragma warning(disable:4996)
using namespace std;
const int N = 310;
const int M = 9;
int val[N][N];
int mm[N];
int dpmax[N][N][M][M];
void initRMQ(int n, int m)
{
for (int i = 1; i <= n; i++)
for (int j = 1; j <= m; j++)
dpmax[i][j][0][0] = val[i][j];
for (int ii = 0; ii <= mm[n]; ii++)
for (int jj = 0; jj <= mm[m]; jj++)
if (ii + jj)
for (int i = 1; i + (1 << ii) - 1 <= n; i++)
for (int j = 1; j + (1 << jj) - 1 <= m; j++)
{
if (ii)
{
dpmax[i][j][ii][jj] = max(dpmax[i][j][ii - 1][jj], dpmax[i + (1 << (ii - 1))][j][ii - 1][jj]);
}
else
{
dpmax[i][j][ii][jj] = max(dpmax[i][j][ii][jj - 1], dpmax[i][j + (1 << (jj - 1))][ii][jj - 1]);
}
}
}
int rmq1(int x1, int y1, int x2, int y2)
{
int k1 = mm[x2 - x1 + 1];
int k2 = mm[y2 - y1 + 1];
x2 = x2 - (1 << k1) + 1;
y2 = y2 - (1 << k2) + 1;
return max(max(dpmax[x1][y1][k1][k2], dpmax[x1][y2][k1][k2]), max(dpmax[x2][y1][k1][k2], dpmax[x2][y2][k1][k2]));
}
int main()
{
mm[0] = -1;
for (int i = 1; i <= 300; i++)
mm[i] = ((i&(i - 1)) == 0) ? mm[i - 1] + 1 : mm[i - 1];
int n, m;
while (~scanf("%d%d", &n, &m))
{
for (int i = 1; i <= n; i++)
for (int j = 1; j <= m; j++)
scanf("%d", &val[i][j]);
initRMQ(n, m);
int x, y, x1, y1;
int Q;
scanf("%d", &Q);
while (Q--)
{
scanf("%d%d%d%d", &x, &y, &x1, &y1);
if (x > x1)
swap(x, x1);
if (y > y1)
swap(y, y1);
int mmax = rmq1(x, y, x1, y1);
if (val[x][y] == mmax || val[x][y1] == mmax || val[x1][y] == mmax || val[x1][y1] == mmax)
{
printf("%d yes\n", mmax);
}
else
{
printf("%d no\n", mmax);
}
}
}
return 0;
}