Submission #335455

#	Time	Username	Problem	Language	Result	Execution time	Memory
335455		gozonite	Traffic (IOI10_traffic)	C++14	100 / 100	1378 ms	186452 KiB

traffic

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<pair<int, int>> vii;
typedef pair<int, int> pi;

vector<int> adj[1000000];
ll p[1000000];
ll sub[1000000];
ll res;
ll mt[1000000];

void dfs(int u, int par, ll pc) {
    ll tsum = 0, mv = 0; 
    for (auto v : adj[u]) {
        if (v == par) continue;
        tsum += sub[v];
        mv = max(mv, sub[v]);
    }
    mt[u] = max(mv, pc);
    for (auto v : adj[u]) {
        if (v == par) continue;
        dfs(v, u, pc+tsum-sub[v]+p[u]);
    }
}

ll gsum(int u, int par) {
    ll tsum = p[u];
    for (auto v : adj[u]) {
        if (v == par) continue;
        tsum += gsum(v, u);
    }
    sub[u] = tsum;
    return sub[u];
}

int LocateCentre(int N, int P[], int S[], int D[]) {
    for (int i = 0; i < N; i++) adj[i].clear();
    for (int i = 0; i < N; i++) p[i] = P[i];
    res = 1e18;
    //fill(mt, mt+N, 0);
    for (int i = 0; i < N-1; i++) {
        int a = S[i], b = D[i];
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    gsum(0, -1);
    dfs(0, -1, 0);
    //cout << "Debugging array" << endl;
    //for (int i = 0; i < N; i++) cout << mt[i] << " "; cout << endl;
    //for (int i = 0; i < N; i++) cout << sub[i] << " "; cout << endl;
    
    int mi = 0;
    for (int i = 1; i < N; i++) {
        if (mt[i] < mt[mi]) mi = i;
    }
    return mi;
}

• Subtask 1: 25 / 25
• Subtask 2: 25 / 25
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25