Submission #226178

#	Time	Username	Problem	Language	Result	Execution time	Memory
226178		Minnakhmetov	Making Friends on Joitter is Fun (JOI20_joitter2)	C++14	17 / 100	148 ms	24440 KiB

joitter2

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define all(aaa) aaa.begin(), aaa.end()

const int N = 2005;
bool gr[N][N], ing[N][N], mem[N][N];
int w[N];
ll ans = 0;
int n, m;

int find_set(int x) {
	return w[x] < 0 ? x : w[x] = find_set(w[x]);
}

void mrg(int x, int y) {
	x = find_set(x);
	y = find_set(y);

	if (x == y)
		return;

	if (w[x] > w[y]) {
		swap(x, y);
	}

	ans -= w[x] * (w[x] + 1);
	ans -= w[y] * (w[y] + 1);

	// cout << w[x] * (w[x] + 1) + w[y] * (w[y] + 1) << "\n";

	for (int i = 0; i < n; i++) {
		if (ing[x][i] && !mem[x][i]) {
			ans += w[x];
		}

		if (ing[y][i] && !mem[y][i]) {
			ans += w[y];
		}

		if (mem[y][i])
			mem[x][i] = true;

		if (ing[y][i]) {
			ing[x][i] = true;
		}
	}

	w[x] += w[y];
	w[y] = x;

	ans += w[x] * (w[x] + 1);

	

	for (int i = 0; i < n; i++) {
		if (ing[x][i] && !mem[x][i]) {
			ans -= w[x];
		}
	}

	for (int i = 0; i < n; i++) {
		if (gr[i][y])
			gr[i][x] = true;
		if (gr[y][i])
			gr[x][i] = true;
	}

	for (int i = 0; i < n; i++) {
		if (gr[x][i] && gr[i][x])
			mrg(x, i);
	}
}

void add_edge(int x, int y) {
	y = find_set(y);

	if (!ing[y][x]) {
		ans -= w[y];
		ing[y][x] = true;
	}

	x = find_set(x);

	if (x == y || gr[x][y])
		return;

	gr[x][y] = true;

	if (gr[y][x])
		mrg(x, y);
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> m;

    fill(w, w + n, -1);

    for (int i = 0; i < n; i++) {
    	mem[i][i] = true;
    }

    for (int i = 0; i < m; i++) {
    	int x, y;
    	cin >> x >> y;
    	x--, y--;

    	add_edge(x, y);
    	cout << ans << "\n";
    }
    
    return 0;
}       

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 0 / 83