MMATRIX - SHIFT Operator on Matrix
Tác giả: ladpro98
Ngôn ngữ: C++
#include <bits/stdc++.h>
using namespace std;
const int N = 123;
const int INF = 0x3f3f3f3f;
int a[N][N];
int sum[N], newSum[N];
int n, ans;
void backtrack(int row) {
if (row > n) {
ans = *max_element(sum + 1, sum + 1 + n);
return;
}
for (int shift = 0; shift < n; ++shift) {
for (int i = 1; i <= n; ++i) newSum[i] = sum[i] + a[row][i + shift];
if (*max_element(newSum + 1, newSum + 1 + n) >= ans) continue;
for (int i = 1; i <= n; ++i) sum[i] = newSum[i];
backtrack(row + 1);
for (int i = 1; i <= n; ++i) sum[i] -= a[row][i + shift];
}
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
while (cin >> n) {
if (n == -1) break;
for (int i = 1; i <= n; ++i) for (int j = 1; j <= n; ++j) cin >> a[i][j];
for (int i = 1; i <= n; ++i) for (int j = 1; j <= n; ++j) a[i][j + n] = a[i][j];
for (int i = 1; i <= n; ++i) sum[i] = a[1][i];
ans = INF;
backtrack(2);
cout << ans << '\n';
}
return 0;
}