Submission #390988

#	Time	Username	Problem	Language	Result	Execution time	Memory
390988		Sorting	Traffic (IOI10_traffic)	C++17	100 / 100	1423 ms	166696 KiB

traffic

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

using namespace std;

const int N = 1e6 + 3;

int n, *p, *s, *d, sz[N], sum_all = 0, ans, ver_ans;
vector<int> adj[N];

void dfs_solve(int u, int par = -1){
    int sum = 0, mx = 0;
    for(int to: adj[u])
        if(to != par){
            dfs_solve(to, u);
            mx = max(mx, sz[to]);
            sum += sz[to];
        }
    mx = max(mx, sum_all - sum - p[u]);
    if(mx < ans){
        ans = mx;
        ver_ans = u;
    }
}

void dfs_sz(int u, int par = -1){
    sz[u] = p[u];
    for(int to: adj[u])
        if(to != par){
            dfs_sz(to, u);
            sz[u] += sz[to];
        }
}

int LocateCentre(int _n, int _p[], int _s[], int _d[]) {
    n = _n, p = _p, s = _s, d = _d;
    for(int i = 0; i < n; ++i)
        adj[i].clear();
    for(int i = 0; i < n - 1; ++i){
        adj[s[i]].push_back(d[i]);
        adj[d[i]].push_back(s[i]);
    }
    sum_all = 0, ans = INT_MAX;
    for(int i = 0; i < n; ++i)
        sum_all += p[i];
    dfs_sz(0);
    dfs_solve(0);
    return ver_ans;
}
/*
5
10 10 10 20 20
0 2
1 2
2 3
3 4
*/

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