Submission #1011801

#	Time	Username	Problem	Language	Result	Execution time	Memory
1011801		yeediot	Duathlon (APIO18_duathlon)	C++17	49 / 100	60 ms	33640 KiB

count_triplets

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
#ifdef local
void CHECK();
void setio(){
    freopen("/Users/iantsai/cpp/input.txt","r",stdin);
    freopen("/Users/iantsai/cpp/output.txt","w",stdout);
}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
#define TOI_is_so_de ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);setio();
const int mxn = 2e5;
vector<int>adj[mxn], st, adj2[mxn];
int n, m, low[mxn], lv[mxn], tmr = 0, w[mxn], cnt, siz[mxn], num;
void tarjan(int v, int pa = -1){
    st.pb(v);
    w[v] = -1;
    low[v] = lv[v] = ++tmr;
    num++;

    for(auto u : adj[v]){
        if(u == pa) continue;
        if(lv[u]){
            chmin(low[v], lv[u]);
        }
        else{
            tarjan(u, v);
            chmin(low[v], low[u]);
            if(low[u] >= lv[v]){
                cnt++;
                int k;
                do{
                    k = st.back();
                    st.pop_back();
                    adj2[k].pb(cnt);
                    adj2[cnt].pb(k);
                }while(k != u);
                adj2[v].pb(cnt);
                adj2[cnt].pb(v);
                w[cnt] = sz(adj2[cnt]);
            }
        }
    }
}
int dp[mxn];
void dfs(int v, int pa = -1){
    siz[v] = (v <= n);
    for(auto u : adj2[v]){
        if(u == pa) continue;
        dfs(u, v);
        dp[v] += siz[v] * siz[u] * w[v] * 2;
        siz[v] += siz[u];
    }
    dp[v] += siz[v] * (num - siz[v]) * w[v] * 2;
}
signed main(){
    TOI_is_so_de;
    cin >> n >> m;
    cnt = n;
    for(int i=0;i<m;i++){
        int a, b;
        cin >> a >> b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    int ans = 0;
    for(int i=1;i<=n;i++){
        if(!lv[i]) {
            num = 0;
            tarjan(i);
            dfs(i);
        }
    }
    for(int i=1;i<=2*n;i++){
        ans += dp[i];
        //cerr << w[i] << ',' << lv[i] << ',' << dp[i] << '\n';
    }
    cout << ans << '\n';
    #ifdef local
    CHECK();
    #endif
}
/*
input:
 
*/
#ifdef local
void CHECK(){
    cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
     function<bool(string,string)> compareFiles = [](string p1, string p2)->bool {
         std::ifstream file1(p1);
         std::ifstream file2(p2);
         if (!file1.is_open() || !file2.is_open())return false;
         std::string line1, line2;
         while (getline(file1, line1) && getline(file2, line2)) {
             if (line1 != line2)return false;
         }
         int cnta=0,cntb=0;
         while(getline(file1,line1))cnta++;
         while(getline(file2,line2))cntb++;
         return cntb-cnta<=1;
     };
     bool check = compareFiles("output.txt","expected.txt");
     if (check) cerr<<"ACCEPTED\n";
     else cerr<<"WRONG ANSWER!\n";
}
#else
#endif



 

Compilation message (stderr)

count_triplets.cpp: In function 'void setIO(std::string)':
count_triplets.cpp:35:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
count_triplets.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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