Submission #961368

#	Time	Username	Problem	Language	Result	Execution time	Memory
961368		TAhmed33	Netrpeljivost (COI23_netrpeljivost)	C++98	100 / 100	1236 ms	80200 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n, a[2049][2049];
const ll inf = 1e18;
void chmin (ll &x, ll y) {
	if (x > y) x = y;
}
vector <vector <ll>> recurse (int l, int r) {
	int sze = r - l + 1; 
	vector <vector <ll>> dp(sze, vector <ll> (sze, inf));
	if (l == r - 1) {
		dp[0][1] = dp[1][0] = a[l][r];
		return dp;
	}
	sze >>= 1;
	int mid = (l + r) >> 1;
	auto g = recurse(l, mid), h = recurse(1 + mid, r);
	for (int i = 0; i < sze; i++) {
		for (int j = 0; j < sze; j++) {
			ll mn = inf;
			for (int k = 0; k < sze; k++) {
				chmin(mn, g[i][k] + a[k + l][j + mid + 1]);
			}
			for (int k = 0; k < sze; k++) {
				chmin(dp[i][k + sze], mn + h[j][k]);
			}
		}	
	}
	sze <<= 1;
	for (int i = 0; i < (sze >> 1); i++) for (int j = (sze >> 1); j < sze; j++) dp[j][i] = dp[i][j];
	return dp;
}
signed main () {
	ios::sync_with_stdio(0); cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			cin >> a[i][j];
		}
	}
	if (n == 2) {
		cout << a[1][2] << '\n';
		return 0;
	}
	auto g = recurse(1, n / 2), h = recurse(n / 2 + 1, n);
	ll mn[n / 2 + 1][2];
	for (int i = 0; i <= n / 2; i++) {
		for (int j = 0; j < 2; j++) {
			mn[i][j] = inf;
		}
	}
	ll ans = inf;
	for (int i = 0; i < n / 2; i++) {
		for (int j = 0; j < n / 2; j++) {
			chmin(mn[i][0], g[i][j]);
			chmin(mn[i][1], h[i][j]);
		}
	}
	for (int i = 0; i < n / 2; i++) {
		for (int j = 0; j < n / 2; j++) {
			chmin(ans, mn[i][0] + mn[j][1] + a[i + 1][j + n / 2 + 1]);
		}
	}
	cout << ans << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 17 / 17
• Subtask 3: 32 / 32
• Subtask 4: 41 / 41