COCI/2010-2011/Contest #1 - 22.10.2010/matrix/bruteforce.cpp

   1 // Andrés Mejía
   2 using namespace std;
   3 #include <algorithm>
   4 #include <iostream>
   5 #include <iterator>
   6 #include <numeric>
   7 #include <sstream>
   8 #include <fstream>
   9 #include <cassert>
  10 #include <climits>
  11 #include <cstdlib>
  12 #include <cstring>
  13 #include <string>
  14 #include <cstdio>
  15 #include <vector>
  16 #include <cmath>
  17 #include <queue>
  18 #include <deque>
  19 #include <stack>
  20 #include <list>
  21 #include <map>
  22 #include <set>
  23
  24 #define foreach(x, v) for (typeof (v).begin() x=(v).begin(); x !=(v).end(); ++x)
  25 #define For(i, a, b) for (int i=(a); i<(b); ++i)
  26 #define D(x) cout << #x " is " << x << endl
  27
  28 const double EPS = 1e-9;
  29 int cmp(double x, double y = 0, double tol = EPS) {
  30     return (x <= y + tol) ? (x + tol < y) ? -1 : 0 : 1;
  31 }
  32
  33 const int MAXN = 405;
  34 int mat[MAXN][MAXN];
  35
  36 vector<int> A[2 * MAXN], B[2 * MAXN];
  37
  38 int main(){
  39     int n;
  40     scanf("%d", &n);
  41     for (int i = 0; i < n; ++i) {
  42         for (int j = 0; j < n; ++j) {
  43             scanf("%d", &mat[i][j]);
  44         }
  45     }
  46     int ans = 0;
  47     for (int i = 0; i < n; ++i) {
  48         for (int j = 0; j < n; ++j) {
  49             for (int delta = 0; i + delta < n and j + delta < n; ++delta) {
  50                 int option = 0;
  51                 for (int k = 0; k <= delta; ++k) {
  52                     option += mat[i+k][j+k];
  53                     option -= mat[i+k][j+delta-k];
  54                 }
  55                 ans = max(option, ans);
  56             }
  57         }
  58     }
  59     cout << ans << endl;
  60     return 0;
  61 }