Submission #487131

#	Time	Username	Problem	Language	Result	Execution time	Memory
487131		Spade1	Traffic (IOI10_traffic)	C++14	100 / 100	904 ms	170680 KiB

traffic

#include <bits/stdc++.h>
#include "traffic.h"
#define ll long long
#define pii pair<int, int>
#define st first
#define nd second
#define pb push_back
using namespace std;

const int maxN = 1e6 + 10;

vector<int> adj[maxN];
int prt[maxN], dis[maxN];

int dfs(int i, int p) {
    for (auto j : adj[i]) {
        if (j == p) continue;
        dis[i] += dfs(j, i);
        prt[j] = i;
    }
    return dis[i];
}

int LocateCentre(int N, int P[], int S[], int D[]) {
    for (int i = 0; i < N - 1; ++i) {
        adj[S[i]].pb(D[i]);
        adj[D[i]].pb(S[i]);
    }

    for (int i = 0; i < N; ++i) {
        dis[i] = P[i];
    }

    dfs(0, -1);

    int ans = 2e9, c;

    for (int i = 0; i < N; ++i) {
        int tmp = 0;
        for (auto j : adj[i]) {
            if (j == prt[i]) tmp = max(tmp, dis[0] - dis[i] );
            else tmp = max(tmp, dis[j]);
        }
        if (tmp < ans) c = i, ans = tmp;
    }

    return c;
}

Compilation message (stderr)

traffic.cpp: In function 'int LocateCentre(int, int*, int*, int*)':
traffic.cpp:47:12: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
   47 |     return c;
      |            ^

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