정수 사각형 최대 합.cpp

정수 사각형 최대 합.cpp

#include <iostream>
using namespace std;

int board[105][105], dp[105][105];

int main() {
  cin.tie(0);
  ios::sync_with_stdio(0);

  int n;
  cin >> n;

  for (int i = 1; i <= n; i++) 
    for (int j = 1; j <= n; j++)
      cin >> board[i][j];

  // dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]) + board[i][j]
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      int prev = 0;

      if ((i - 1 >= 1 && i - 1 <= n) && (j >= 1 && j <= n))  
        prev = max(prev, dp[i - 1][j] ? dp[i - 1][j] : board[i - 1][j]);
      
      if ((i >= 1 && i <= n) && (j - 1 >= 1 && j - 1 <= n)) 
        prev = max(prev, dp[i][j - 1] ? dp[i][j - 1] : board[i][j - 1]);

      dp[i][j] = prev + board[i][j];
    }
  }

  int max_val = 0;
  for (int i = 1; i <= n; i++) 
    for (int j = 1; j <= n; j++) 
      if (max_val < dp[i][j]) max_val = dp[i][j];

  cout << max_val << '\n';
}