Submission #252841

#	Time	Username	Problem	Language	Result	Execution time	Memory
252841		SamAnd	Traffic (IOI10_traffic)	C++17	100 / 100	1234 ms	166904 KiB

traffic

#include "traffic.h"
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
using namespace std;
const int N = 1000003,INF=2000000001;

int n;
vector<pair<int,int> > a[N];
int b[N];
int sum, ans = INF, ansi;
int dfs(int x, int p)
{
	int res=0;
	int yans=0;
	for (int i = 0; i < a[x].size(); ++i)
	{
		int h = a[x][i].first;
		if (h == p)
			continue;
		a[x][i].second = dfs(h,x);
		res += a[x][i].second;
		yans = max(yans, a[x][i].second);
	}
	yans = max(yans, sum - res - b[x]);
	if (yans < ans)
	{
		ans = yans;
		ansi = x;
	}
	return res + b[x];
}
int LocateCentre(int N, int pp[], int S[], int D[]) {
	n = N;
	for (int i = 0; i < n; ++i)
	{
		b[i] = pp[i];
		sum += b[i];
	}
	for (int i = 0; i < n - 1; ++i)
	{
		a[S[i]].push_back(make_pair(D[i],0));
		a[D[i]].push_back(make_pair(S[i],0));
	}
	dfs(0,-1);
	return ansi;
}

Compilation message (stderr)

traffic.cpp: In function 'int dfs(int, int)':
traffic.cpp:17:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < a[x].size(); ++i)
                  ~~^~~~~~~~~~~~~

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