Submission #854965

#	Time	Username	Problem	Language	Result	Execution time	Memory
854965		thinknoexit	Traffic (IOI10_traffic)	C++17	100 / 100	945 ms	182992 KiB

traffic

#include <bits/stdc++.h>
#include "traffic.h"
using namespace std;
using ll = long long;
const ll INF = 1e18;
const int N = 1001000;
ll dp[2][N];
vector<int> adj[N];
int a[N], ans = -1;
ll mn = INF;
void dfs(int v, int p = -1) {
    dp[0][v] = dp[1][v] = 0;
    for (auto& x : adj[v]) {
        if (x == p) continue;
        dfs(x, v);
        dp[0][v] += dp[0][x] + a[x];
        dp[1][v] = max(dp[1][v], dp[0][x] + a[x]);
    }
}
void dfs2(int v, int p = -1, ll w = 0) {
    if (max(w, dp[1][v]) < mn) {
        mn = max(w, dp[1][v]);
        ans = v;
    }
    for (auto& x : adj[v]) {
        if (x == p) continue;
        dfs2(x, v, dp[0][v] - dp[0][x] - a[x] + a[v] + w);
    }
}
int LocateCentre(int n, int p[], int s[], int d[]) {
    for (int i = 0;i < n;i++) {
        a[i] = p[i];
    }
    for (int i = 0;i < n - 1;i++) {
        adj[s[i]].push_back(d[i]);
        adj[d[i]].push_back(s[i]);
    }
    dfs(0);
    dfs2(0);
    return ans;
}

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