Submission #1111692

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111692		imarn	Duathlon (APIO18_duathlon)	C++14	0 / 100	147 ms	114692 KiB

count_triplets

#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define plx pair<ll,int>
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()
#define sz(x) (ll)x.size()
#define vi vector<int>
#define vvi vector<vi>
#define pp pair<ll,int>
#define ub(x,i) upper_bound(all(x),i)-x.begin()
using namespace std;
const int mxn=2e6+5;
vector<int>h,g[mxn],st;
vector<int>gg[mxn];
bool vis[mxn]{0};
int di[mxn]{0},lo[mxn]{0},cur=0;
ll cnt=0,n;
ll sz[mxn]{0};
void dfs(int u,int p){
    di[u]=lo[u]=++cur;
    st.pb(u);cnt++;
    for(auto v:g[u]){
        if(!di[v]){
            dfs(v,u);
            lo[u]=min(lo[u],lo[v]);
            if(lo[v]>=di[u]){
                while(st.back()!=v){
                    gg[v+n].pb(st.back());
                    st.pop_back();
                }gg[v+n].pb(v);st.pop_back();
                gg[u].pb(v+n);
            }
        }else if(v!=p){
            lo[u]=min(lo[u],di[v]);
        }
    }
}ll rs=0;
void solve(int u,int p){
    if(u<=n)sz[u]=1;
    for(auto v:gg[u]){
        if(v==p)continue;
        solve(v,u);sz[u]+=sz[v];
        if(u>n)rs-=sz(gg[u])*(sz[v])*(sz[v]-1);
    }
    if(u>n)rs-=sz(gg[u])*(n-sz[u])*(n-sz[u]-1);
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int m;cin>>n>>m;
    for(int i=1;i<=m;i++){
        int a,b;cin>>a>>b;g[a].pb(b);g[b].pb(a);
    }
    for(int i=1;i<=n;i++){
        if(di[i])continue;cnt=0;
        dfs(i,i);st.clear();
        rs+=cnt*(cnt-1)*(cnt-2);
        solve(i,i);
    }cout<<rs;
}

Compilation message (stderr)

count_triplets.cpp: In function 'int main()':
count_triplets.cpp:58:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   58 |         if(di[i])continue;cnt=0;
      |         ^~
count_triplets.cpp:58:27: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   58 |         if(di[i])continue;cnt=0;
      |                           ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10