Submission #1234061

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234061		Geforgs	Hotspot (NOI17_hotspot)	C++20	64 / 100	45 ms	584 KiB

hotspot

#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <unordered_map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ld long double
#define inf (ll)(2*1e18)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define pb push_back
#define endl "\n"
using namespace std;

ll gcd(ll a, ll b){
    if(a == 0) return b;
    return gcd(b%a, a);
}

struct fraction{
    ll x=0, y=1;
    bool operator>(fraction& another){
        return x*another.y > y*another.x;
    }
    void div(){
        ll g = gcd(x, y);
        x /= g;
        y /= g;
    }
};

void find(ll n, ll x, ll y, vector<vector<ll>>& a, vector<fraction>& ans){
    vector<ll> dis1(n, -1);
    vector<ll> dis2(n, -1);
    vector<ll> cnt1(n, 0);
    vector<ll> cnt2(n, 0);
    queue<ll> que;
    dis1[x] = 0;
    cnt1[x] = 1;
    que.push(x);
    while(!que.empty()){
        auto z = que.front();
        que.pop();
        for(auto el: a[z]){
            if(dis1[el] == -1){
                dis1[el] = dis1[z] + 1;
                que.push(el);
            }
            if(dis1[el] == dis1[z] + 1){
                cnt1[el] += cnt1[z];
            }
        }
    }
    dis2[y] = 0;
    cnt2[y] = 1;
    que.push(y);
    while(!que.empty()){
        auto z = que.front();
        que.pop();
        for(auto el: a[z]){
            if(dis2[el] == -1){
                dis2[el] = dis2[z] + 1;
                que.push(el);
            }
            if(dis2[el] == dis2[z] + 1){
                cnt2[el] += cnt2[z];
            }
        }
    }
    if(dis1[y] == -1) return;
    ll dis = dis1[y], cnt=cnt1[y], b, c, g;
    for(int i=0;i<n;++i){
        if(dis1[i] + dis2[i] == dis and dis1[i] != -1 and dis2[i] != -1){
            b = (cnt1[i]*cnt2[i]);
            c = cnt;
            g = gcd(b, c);
            b /= g;
            c /= g;
            ans[i].x *= c;
            ans[i].x += b*ans[i].y;
            ans[i].y *= c;
            ans[i].div();
        }
    }
}

void solve(){
    ll n, m, k, i, x, y, answer=0;
    fraction res;
    cin>>n>>m;
    vector<vector<ll>> a(n);
    vector<fraction> ans(n);
    for(i=0;i<m;++i){
        cin>>x>>y;
        a[x].pb(y);
        a[y].pb(x);
    }
    cin>>k;
    for(i=0;i<k;++i){
        cin>>x>>y;
        find(n, x, y, a, ans);
    }
    for(i=0;i<n;++i){
        if(ans[i] > res){
            res = ans[i];
            answer = i;
        }
    }
    cout<<answer<<endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    srand(time(nullptr));
    ll t=1;
//    cin>>t;
    for(;t>0;--t){
        solve();
    }
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 18 / 18
• Subtask 5: 26 / 26
• Subtask 6: 0 / 36