Submission #1370421

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Source Code Expand

#include <bits/stdc++.h>
 
#define pii pair<int, int>
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define ll long long 
#define ull unsigned long long 
#define ld long double
#define sz(v) int(v.size())
#define all(v) v.begin(), v.end()
 
#define y1 what
 
using namespace std;
 
const int N = (int) 1e5 + 10;
const int M = (int) 101;
const ll big =  (1LL << 51);
const ll LINF = (ll) 1e18;
const int INF = (int) 1e9 + 7;
const int INF1 = (int) 1e9 + 3;
const double EPS = (double) 1e-6;
const double PI =  3.14159265359;
 
int n, m;
vector<int> v[N];
int u[N], cycle;
 
void dfs(int x, int p = -1) {
  u[x] = 1;
  for (auto it : v[x]) {
    if (it == p) 
        continue;
    if (!u[it]) 
        dfs(it, x);
    else if (u[it] == 1) {
        cycle = 1;
    }
  }
  u[x] = 2;
}
 
int deg[N];

int main() {
    #define fn "balls"
    #ifdef witch
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #else
//        freopen(fn".in", "r", stdin);
//        freopen(fn".out", "w", stdout);
    #endif
    srand(time(0));
    cin >> n >> m;
    vector<pii> e;
    while (m--) {
      int x, y;
      cin >> x >> y;
      --x, --y;
      e.pb({x, y});
      e.pb({y, x});
      v[x].pb(y);
      v[y].pb(x);
      ++deg[x];
      ++deg[y];
    }
    /*
    for (int i = 0; i < sz(e); i++) {
      for (int j = 0; j < sz(e); j++) {
        v[e[i].f * n + e[j].f].pb(e[i].s * n + e[j].s);
      }
    }
    */
    ll comp = 0, diger = 0, cnt = 0;
    for (int i = 0; i < n; i++) {
        if (!deg[i]) {
            comp += n + n - 1;
        } else if (!u[i]) {
            cycle = 0;
            dfs(i);
            ++diger;
            //diger = 2 - cycle;
            //comp += 2 * diger - 1;
        }
    }
    //cout << diger << endl;
    cout << comp + 2 + (diger - 1) * 3;
    return 0;
}

Submission Info

Judge Result