Submission #499558

#	Time	Username	Problem	Language	Result	Execution time	Memory
499558		iwantin	Traffic (IOI10_traffic)	C++17	Compilation error	0 ms	0 KiB

traffic

#include <bits/stdc++.h>
using namespace std;

#define M_PI 3.14159265358979323846 
#define pb push_back
#define fs first
#define sc second

typedef long long ll;
typedef long double ld;

const ll mod = 1e9 + 7;
const ll maxn = 1e6 + 1;
const ll inf = 	LLONG_MAX;
const ll minf = LLONG_MIN; 

vector <ll> cost(maxn), dist(maxn),
children(maxn), ans(maxn);
vector <vector <ll> > g(maxn);
vector <bool> used(maxn);
ll n;

ll findChildren(ll v){
	used[v] = true;
	children[v] = 1;

	for(auto i: g[v])
		if(!used[i])
			children[v] += findChildren(i);

	return children[v];
}

ll findDist(ll v){
	used[v] = true;
	ll isZero = !(v == 0), num = 0;  

	ans[0] += cost[v] * children[v] * isZero;

	for(auto i: g[v])
		if(!used[i])
			num += findDist(i);

	dist[v] = num + cost[v] * children[v] * isZero;
	
	return dist[v];
}

void findAns(ll v, ll parent = -1){
	used[v] = true;

	if(parent != -1){
		ans[v] = cost[parent] * (n - children[parent] + 1) + ans[parent];
		ans[v] -= cost[v] * (children[v]); 	  
	}  

	for(auto i: g[v])
		if(!used[i])
			findAns(i, v);

}

int main(){
	
	ios_base :: sync_with_stdio(false);
	cin.tie(NULL);

	cin>>n;

	for(ll k = 0; k < n; k++)
		cin>>cost[k];

	for(ll k = 0; k < n - 1; k++){
		ll a, b; cin>>a>>b;
		g[a].pb(b);
		g[b].pb(a);
	}

	findChildren(0); 

	for(ll k = 0; k < n; k++)
		used[k] = false;
	
	findDist(0);

	for(ll k = 0; k < n; k++)
		used[k] = false;
	
	findAns(0);
	
	ll mn = LLONG_MAX, ansk = 0;

	for(ll k = 0; k < n; k++){
		if(ans[k] < mn){
			mn = ans[k];
			ansk = k;
		}
	}

	cout<<ansk;
	return 0;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/cc6Pi40r.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cciR3Pbw.o:traffic.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cc6Pi40r.o: in function `main':
grader.cpp:(.text.startup+0xe1): undefined reference to `LocateCentre(int, int*, int*, int*)'
collect2: error: ld returned 1 exit status