Submission #254236

#	Time	Username	Problem	Language	Result	Execution time	Memory
254236		tatyam	Traffic (IOI10_traffic)	C++17	Compilation error	0 ms	0 KiB

traffic

#include <bits/stdc++.h>
using namespace std;
template<class T, class U> bool chmax(T& a, const U& b){ if(a < b){ a = b; return 1; } return 0; }


int LocateCentre(int n, int p[], int s[], int d[]){
    const int sum = reduce(p, p + n, 0);
    vector<vector<int>> g(n);
    for(int i = 0; i < n - 1; i++){
        const int a = s[i], b = d[i];
        g[a].push_back(b);
        g[b].push_back(a);
    }
    vector<int> siz(n, 1), dp(n);
    auto dfs = [&](int from, int at, const auto& dfs) -> void {
        for(int i : g[at]) if(i != from){
            dfs(at, i, dfs);
            chmax(dp[at], siz[i]);
            siz[at] += siz[i];
        }
        chmax(dp[at], sum - siz[at]);
    };
    dfs(-1, 0, dfs);
    return min_element(dp.begin(), dp.end()) - dp.begin();
}

Compilation message (stderr)

traffic.cpp: In function 'int LocateCentre(int, int*, int*, int*)':
traffic.cpp:7:21: error: 'reduce' was not declared in this scope
     const int sum = reduce(p, p + n, 0);
                     ^~~~~~
traffic.cpp:7:21: note: suggested alternative: 'rename'
     const int sum = reduce(p, p + n, 0);
                     ^~~~~~
                     rename