10667 - Largest Block, uva

#include<iostream>
#include<cstdio>
#include<cstring>
#define db(a) cout << #a << " = " << a << endl
#define db2(a, b) cout << #a << " = " << a << " " << #b << " = " << b << endl
#define db3(a, b, c) cout << #a << " = " << a << " " << #b << " = " << b << " " << #c << " = " << c << endl
using namespace std;
int main() {
 #ifdef dennisbot
  freopen("in.in", "r", stdin);
  //freopen("ou.out", "w", stdout);
 #endif
 int p, s, b, r1, c1, r2, c2, matriz[101][101], fila[101], max, sum;
 scanf("%d", &p);
 for (;p; p--) {
  scanf("%d", &s);
  for (int i = 0; i < s; i++)
   for (int j = 0; j < s; j++)
    matriz[i][j] = 1;
  scanf("%d", &b);
  for (int k = 0; k < b; k++) {
   scanf("%d%d%d%d", &r1, &c1, &r2, &c2);
   r1--, c1--, r2--, c2--;
   for (int i = r1; i <= r2; i++) {
    for (int j = c1; j <= c2; j++) {
     matriz[i][j] = 0;
    }
   }
  }
  max = 0;
  for (int i = 0; i < s; i++) {
  
   for(int k = 0; k < s; k++) fila[k] = 0;
   
   for (int ii = i; ii < s; ii++) {
    sum = 0;
    for (int j = 0; j < s; j++) {
     fila[j] += matriz[ii][j];
     if (fila[j] == ii - i + 1) sum += fila[j];
     else sum = 0;
     if (sum > max) max = sum;
    }
   }
  }
  printf("%d\n", max);
  
 }
 return 0;
}