제출 #501486

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
501486		kaxzert	철인 이종 경기 (APIO18_duathlon)	C++17	0 / 100	104 ms	39436 KiB

count_triplets

/**
      ⚡⚡  ⚡⚡      ⚡⚡⚡     ⚡⚡  ⚡⚡  ⚡⚡⚡⚡⚡⚡   ⚡⚡⚡⚡⚡  ⚡⚡⚡⚡⚡⚡  ⚡⚡⚡⚡⚡⚡
      ⚡⚡ ⚡⚡      ⚡⚡⚡⚡     ⚡⚡⚡⚡      ⚡⚡      ⚡⚡       ⚡⚡    ⚡⚡  ⚡⚡⚡⚡⚡⚡
      ⚡⚡⚡⚡      ⚡⚡  ⚡⚡      ⚡⚡      ⚡⚡       ⚡⚡⚡⚡⚡   ⚡⚡⚡⚡⚡⚡     ⚡⚡
      ⚡⚡ ⚡⚡    ⚡⚡⚡⚡⚡⚡     ⚡⚡     ⚡⚡         ⚡⚡       ⚡⚡  ⚡⚡       ⚡⚡
      ⚡⚡  ⚡⚡  ⚡⚡     ⚡⚡  ⚡⚡ ⚡⚡  ⚡⚡⚡⚡⚡⚡  ⚡⚡⚡⚡⚡    ⚡⚡   ⚡⚡     ⚡⚡
**/
 
#include<bits/stdc++.h>
 
using namespace std;
 
#define fto(i, a, b) for(int i = a; i <= b; ++i)
#define fdto(i, a, b) for(int i = a; i >= b; --i)
#define bugarr(a, i, j) cout << #a << "{" << i << "..." << j << "}:"; fto(k, i, j-1) cout << a[k] << ", "; cout << a[j] << endl;
#define ll long long
#define db double
#define ldb long double
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define vt vector
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define trav(i, a) for(auto &i : a)
#define sz(a) (int)a.size()
#define pi(a, b) pair<a, b>
#define fast ios::sync_with_stdio(false); cin.tie(0)
 
string to_bit(int n) {
    string res = "";
    while(n > 0) {
        res += to_string(n&1);
        n >>= 1;
    }
    return res;
}
 
 
void setIO(string s) {
    if (sz(s) != 0) {
        freopen((s+".inp").c_str(),"r",stdin);
        freopen((s+".out").c_str(),"w",stdout);
    }
}
 
void setIOusaco(string s) {
    if (sz(s) != 0) {
        freopen((s+".in").c_str(),"r",stdin);
        freopen((s+".out").c_str(),"w",stdout);
    }
}
 
template<typename T, typename V>
bool ckmin(T &a, V b) {return (b < a)? a = b, true : false;}
template<typename T, typename V>
bool ckmax(T &a, V b) {return (b > a)? a = b, true : false;}
 
void print(int x) {cout << x;}
void print(long long x) {cout << x;}
void print(unsigned x) {cout << x;}
void print(unsigned long long x) {cout << x;}
void print(double x) {cout << fixed << x;}
void print(long double x) {cout << fixed << x;}
void print(char x) {cout << "'" << x << "'";}
void print(string x) {cout << '"' << x << '"';}
void print(bool x) {cout << (x ? "true" : "false");}
 
template<typename T, typename V>
void print(const pair<T, V> &x) {cout << '{'; print(x.ff); cout << ", "; print(x.ss); cout << '}';}
template<typename T>
void print(const T &x) {int f = 0; cout << '{'; for (auto &i: x) cout << (f++ ? ", " : ""), print(i); cout << "}";}
void _print() {cout << "]" << endl;}
template <typename T, typename... V>
void _print(T t, V... v) {print(t); if (sizeof...(v)) cout << ", "; _print(v...);}
 
#ifdef TAP
#define bug(x...) cout << "[" << #x << "] = ["; _print(x)
#else
#define bug(x...) 
#endif
 
const int maxN = 100008;
 
int low[maxN], num[maxN*4], cnt, color[maxN], articulation[maxN], root, child, dd[maxN];
vt<int> ke[maxN], block_ke[maxN*4];
ll cnt_color[maxN*4], ans, n, m;
vt<vt<pi(int, int)> > bvccs;
stack<pi(int, int)> s;
 
void dfs(int u, int p = 0) {
    num[u] = low[u] = ++cnt;
    trav(v, ke[u]) {
        if (v == p) continue;
        if (num[v] == 0) {
            s.push({u, v});
            if (u == root) ++child;
            dfs(v, u);
            if (low[v] >= num[u]) {
                articulation[u] = 1;
                vt<pi(int, int)> bvcc;
                while(s.top().ff != u || s.top().ss != v) {
                    bvcc.pb(s.top());
                    s.pop();
                }
                bvcc.pb(s.top());
                s.pop();
                bvccs.pb(bvcc);
            }
            ckmin(low[u], low[v]);
        } else {
            if (num[u] > num[v]) s.push({u, v});
            ckmin(low[u], num[v]);
        }
    }
}
 
ll dfs2(int u, int p = 0, int is_cut = 1) {
    num[u] = 1;
    ll res = (is_cut ? 1 : cnt_color[u]);
    trav(v, block_ke[u]) {
        if (v == p) continue;
        ll sth = dfs2(v, u, is_cut^1);
     //  bug(u, p, is_cut);
     //  bug(sth);
        res += sth;
        if (is_cut == 1) ans += (is_cut ? 1LL : cnt_color[u])*(cnt_color[v]*(cnt_color[v]-1));
        ans -= (is_cut ? 1 : cnt_color[u])*(sth*(sth-1));
      // bug(ans);
    }
    if (is_cut == 1 && p != 0) if (is_cut&1) ans += (is_cut ? 1LL : cnt_color[u])*(cnt_color[p]*(cnt_color[p]-1));
    ans -= (is_cut ? 1 : cnt_color[u])*((n-res)*(n-res-1));
   //  bug(u, p, is_cut);
   //bug(n-res);
   //bug(ans);
    return res;
}
 
int main() {
    #ifndef TAP 
    setIO("");
    //setIOusaco("duatholon2018");
    #endif
 
    fast;
 
    cin >> n >> m;
    fto(i, 1, m) {
        int u, v;
        cin >> u >> v;
        ke[u].pb(v);
        ke[v].pb(u);
    }
 
    fto(i, 1, n) {
        if (num[i] == 0) {
            root = i;
            child = 0;
            dfs(i, 0);
            articulation[i] = (child > 1);
        }
    }
 
    int dem = 0;
    fto(i, 1, n) {
        if (articulation[i]) {
            color[i] = ++dem;
        }
    }
 
    auto add = [&](int u) -> void {
        if (articulation[u]) {
            if (dd[u] != dem) {
                block_ke[dem].pb(color[u]);
                block_ke[color[u]].pb(dem);
                dd[u] = dem;
            }
        } else {
            cnt_color[dem] += dd[u]^1;
            dd[u] |= 1;
            color[u] = dem;
        }
    };
 
    vt<int> dd(n+1, 0);
    trav(bvcc, bvccs) {
        ++dem;
        trav(canh, bvcc) {
            add(canh.ff);
            add(canh.ss);
        }
    }

    // fto(i, 1, n) {
    //     cout << color[i] << ' ';
    // }
    // cout << '\n';
 
    fto(i, 1, dem) {
        num[i] = 0;
    }
    
    ans = n*(n-1)*(n-2);
    fto(i, 1, dem) {
        if (num[i] == 0) {
            dfs2(i);
        }
    }
 
    cout << ans << '\n';
 
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

count_triplets.cpp: In function 'void setIO(std::string)':
count_triplets.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         freopen((s+".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
count_triplets.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen((s+".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
count_triplets.cpp: In function 'void setIOusaco(std::string)':
count_triplets.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen((s+".in").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
count_triplets.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen((s+".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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