Submission #1105342

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105342		ngokhanh	Hotspot (NOI17_hotspot)	C++17	100 / 100	643 ms	848 KiB

hotspot

#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for (int i=a;i<=b;i++)
#define rep2(i,a,b,c) for (int i=a;i<=b;i+=c)
#define rev(i,a,b) for (int i=a;i>=b;i--)
#define rev2(i,a,b,c) for (int i=a;i>=b;i-=c)
#define ii pair<ll,ll>
#define bit(i,j) ((i>>j)&1)
#define ull unsigned long long
#define pb push_back
#define pf push_front
#define ll long long
#define F first
#define S second
#define sz(a) (int)(a.size())
#define on(n) __builtin_popcountll(n)
#define ld long double
#define __log2(x) 63-__builtin_clzll(x)
#define Mask(x) (1LL<<x)
#define ALL(v) v.begin(),v.end()

const int N=5e3+5;
const int mod=998244353;

int n,m,k,u,v,a,b;
int dist[N][2],cnt[N][2];
vector<int> g[N];
bool use[N];
ld ans[N];

void bfs(int s,int p){
    rep(i,1,n){
        use[i]=0;
        dist[s][p]=1e9;
        cnt[i][p]=0;
    }
    queue<int> q;
    q.push(s);
    use[s]=1;
    dist[s][p]=0;
    cnt[s][p]=1;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        for (int v:g[u])
            if (!use[v]){
                use[v]=1;
                dist[v][p]=dist[u][p]+1;
                cnt[v][p]=cnt[u][p];
                q.push(v);
            }
            else if (dist[v][p]==dist[u][p]+1) cnt[v][p]+=cnt[u][p];
    }
}

void solution(){
    cin >> n >> m;
    rep(i,1,m){
        cin >> u >> v;
        u++,v++;
        g[u].pb(v);
        g[v].pb(u);
    }
    cin >> k;
    rep(j,1,k){
        cin >> a >> b;
        a++,b++;
        bfs(a,0);
        bfs(b,1);
        ld Y=cnt[b][0]*1.0;
        rep(i,1,n)
            if (dist[i][0]+dist[i][1]==dist[b][0]){
               ld X=cnt[i][0]*cnt[i][1]*1.0;
               ans[i]=ans[i]*1.0+(X*1.0)/Y;
        }
    }
    int res=0;
    rep(i,1,n) if (ans[i]>ans[res]) res=i;
    cout << res-1;
}
int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int test=1;
    //cin >> test;
    while(test--)
        solution();
}

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