뒤집기 2

#include <iostream> #include <string> #include <vector> using namespace std; int main(void) { int n, m; vector<string> coins; int answer = 0; ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n >> m; coins.resize(n); for (int i = 0; i < n; i++) cin >> coins[i]; for (int i = n - 1; i >= 0; i--) { for (int j = m - 1; j >= 0; j--) { if (coins[i][j] == '1') { for (int row = i; row >= 0; row--) { for (int col = j; col >= 0; col--) { if (coins[row][col] == '1') coins[row][col] = '0'; else coins[row][col] = '1'; } } answer++; } } } cout << answer; return (0); }