Submission #749763

#	Time	Username	Problem	Language	Result	Execution time	Memory
749763		stevancv	Making Friends on Joitter is Fun (JOI20_joitter2)	C++14	0 / 100	3 ms	4948 KiB

joitter2

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 1e5 + 2;
const int inf = 1e9;
int p[N], sz[N], szz[N];
vector<int> arr[N], brr[N];
void Init(int n) {
    for (int i = 1; i <= n; i++) {
        p[i] = i;
        sz[i] = 1;
    }
}
int Find(int x) {
    if (x == p[x]) return p[x];
    return Find(p[x]);
}
ll C(ll x) {
    return x * (x - 1);
}
map<pair<int, int>, int> imaput, strelica;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, m;
    cin >> n >> m;
    Init(n);
    ll ans = 0;
    while (m--) {
        int a, b;
        cin >> a >> b;
        imaput[{a, b}] = 1;
        if (Find(a) == Find(b)) {
            cout << ans << en;
            continue;
        }
        int x = Find(a);
        int y = Find(b);
        if (imaput[{b, a}] != 1) {
            if (strelica.find({y, a}) == strelica.end()) {
                ans += sz[y];
                arr[y].push_back(a);
                brr[x].push_back(y);
                strelica[{y, a}] = 1;
                szz[y] += 1;
            }
            cout << ans << en;
            continue;
        }
        ans += C(sz[x] + sz[y]) - C(sz[x]) - C(sz[y]);
        if (sz[x] < sz[y]) {swap(x, y); swap(a, b);}
        int kol = 0;
        for (int u : arr[y]) {
            int o = Find(u);
            if (o == x) ans -= sz[y];
            else {
                ans += sz[x];
                arr[x].push_back(u);
                strelica[{y, u}] = 0;
                strelica[{x, u}] = 1;
                kol += 1;
            }
        }
        int cnt = szz[x];
        for (int u : brr[y]) {
            int o = Find(u);
            if (o == x) {
                ans -= sz[x];
                cnt -= 1;
                szz[x] -= 1;
            }
            else {
                brr[x].push_back(u);
                arr[o].push_back(y);
            }
        }
        ans += (ll)(cnt * sz[y]);
        sz[x] += sz[y];
        szz[x] += kol;
        p[y] = x;
        cout << ans << en;
    }
    return 0;
}

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