Submission #909514

#	Time	Username	Problem	Language	Result	Execution time	Memory
909514		bachhoangxuan	우호 조약 체결 (JOI14_friends)	C++17	100 / 100	72 ms	19228 KiB

friends

// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/

#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
#define int long long
#define ld long double
#define pii pair<int,int>
#define piii pair<int,pii>
#define mpp make_pair
#define fi first
#define se second
const int inf=1e18;
const int mod=998244353;
const int maxn=200005;
const int bl=650;
const int maxs=655;
const int maxm=200005;
const int maxq=1000005;
const int maxl=25;
const int maxa=1000000;
const int root=3;
int power(int a,int n){
    int res=1;
    while(n){
        if(n&1) res=res*a%mod;
        a=a*a%mod;n>>=1;
    }
    return res;
}
const int iroot=power(3,mod-2);
const int base=131;

vector<int> edge[maxn];
int n,m,par[maxn],x[maxn];
vector<pii> e;

int findpar(int u){
    if(u!=par[u]) return par[u]=findpar(par[u]);
    return u;
}

void unions(int u,int v){
    u=findpar(u);v=findpar(v);
    if(u==v) return;
    if(x[u] && x[v]) e.push_back({x[u],x[v]});
    if(x[v]) e.push_back({u,x[v]});
    if(x[u]) e.push_back({v,x[u]});
    x[u]=max(x[u],x[v]);
    if(!x[u]) x[u]=u;
    par[v]=u;
    return;
}

void solve(){
    cin >> n >> m;
    for(int i=1;i<=m;i++){
        int u,v;cin >> u >> v;
        edge[u].push_back(v);
    }
    for(int i=1;i<=n;i++){
        par[i]=i;
        if(!edge[i].empty()) x[i]=edge[i].back();
        for(int j=1;j<(int)edge[i].size();j++) e.push_back({edge[i][j-1],edge[i][j]});
    }
    while(!e.empty()){
        pii x=e.back();e.pop_back();
        unions(x.fi,x.se);
    }
    int cnt=0;
    map<int,int> mp;
    for(int i=1;i<=n;i++){
        mp[findpar(i)]++;
        for(int v:edge[i]) if(findpar(i)!=findpar(v)) cnt++;
    }
    for(auto x:mp) cnt+=(x.se-1)*x.se;
    cout << cnt << '\n';
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    int test=1;//cin >> test;
    while(test--) solve();
}

• Subtask 1: 5 / 5
• Subtask 2: 30 / 30
• Subtask 3: 65 / 65