Submission #931096

#	Time	Username	Problem	Language	Result	Execution time	Memory
931096		Art_ogo	Dreaming (IOI13_dreaming)	C++17	18 / 100	50 ms	21332 KiB

dreaming

#include <bits/stdc++.h>
#include "dreaming.h"

#define ve vector 
#define all(x) x.begin(), x.end()
#define fi first
#define se second

using namespace std;

typedef pair<int, int> pii;

const int MAXN = 1e5+10;

ve<pii> g[MAXN];
bool vis[MAXN];
int dst[MAXN];
int mxdst[MAXN];

void calcdst(int v){
    vis[v] = 1;
    mxdst[v] = dst[v];
    for(auto to : g[v])
        if(!vis[to.fi]){
            dst[to.fi] = dst[v] + to.se;
            calcdst(to.fi);
            mxdst[v] = max(mxdst[v], mxdst[to.fi]);
        }
}

int dfs(int v, int p, int curmx, int cur){
    ve<int> dsts = {curmx};
    for(auto& to : g[v])
        if(to.fi != p)
            dsts.push_back(mxdst[to.fi] - cur);
    sort(all(dsts), greater<int>());
    int res = dsts[0];
    multiset<int, greater<int> > cdst;
    for(auto i : dsts)
        cdst.insert(i);
    for(auto& to : g[v])
        if(to.fi != p){
            cdst.erase(cdst.find(mxdst[to.fi] - cur));
            res = min(res, dfs(to.fi, v, *cdst.begin() + to.se, cur + to.se));
            cdst.insert(mxdst[to.fi] - cur);
        }
    return res;
}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    for(int i = 0; i < M; i++){
        int u = A[i], v = B[i], w = T[i];
        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }
    ve<int> v;
    for(int i = 0; i < N; i++)
        if(!vis[i]){
            calcdst(i);
            v.push_back(dfs(i, i, 0, 0));
        }
    sort(all(v), greater<int>());
    if(v.size() == 1)
        return v[0];
    else if(v.size() == 2)
        return v[0] + v[1] + L;
    else 
        return max(v[0] + v[1] + L, v[1] + v[2] + 2*L);
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 18 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23