Submission #1028262

#	Time	Username	Problem	Language	Result	Execution time	Memory
1028262		Tob	Traffic (IOI10_traffic)	C++14	Compilation error	0 ms	0 KiB

traffic

#include <bits/stdc++.h>

//#include "traffic.h"

#define F first
#define S second
#define all(x) x.begin(), x.end()
#define pb push_back
#define FIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

using namespace std;

typedef long long ll;
typedef pair <ll, ll> pii;

const int N = 1e6 + 7;

int sum, fo;
int a[N], siz[N], res[N];
vector <int> adj[N];

int dfs(int x, bool rev, int p = -1, int d = 0) {
	if (!rev) {
		siz[x] = a[x];
		for (auto y : adj[x]) if (y != p) siz[x] += dfs(y, 0, x);
		return siz[x];
	}
	int mx = d, cur = x;
	for (auto y : adj[x]) if (y != p) mx = max(mx, siz[y]);
	res[x] = mx;
	for (auto y : adj[x]) if (y != p) {
		int z = dfs(y, 1, x, sum-siz[y]);
		if (res[z] < res[cur]) cur = z;
	}
	return cur;
}

int LocateCentre(int n, int pp[], int S[], int D[]) {
	for (int i = 0; i < n; i++) {
		a[i] = pp[i];
		sum += a[i];
	}
	for (int i = 0; i < n-1; i++) {
		adj[S[i]].pb(D[i]);
		adj[D[i]].pb(S[i]);
	}
	dfs(0, 0);
	return dfs(0, 1);
}

//-----------------------------------------

static int NN,PP[1000000],SS[1000000],DD[1000000];

int main(){
	int i;
	scanf("%d",&NN);
	for (i=0;i<NN;i++) scanf("%d",&PP[i]);
	for (i=0;i<NN-1;i++) scanf("%d%d",&SS[i],&DD[i]);
	int r = LocateCentre(NN,PP,SS,DD);
	printf("%d\n",r);
	return 0;
}

Compilation message (stderr)

traffic.cpp: In function 'int main()':
traffic.cpp:57:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |  scanf("%d",&NN);
      |  ~~~~~^~~~~~~~~~
traffic.cpp:58:26: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |  for (i=0;i<NN;i++) scanf("%d",&PP[i]);
      |                     ~~~~~^~~~~~~~~~~~~
traffic.cpp:59:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |  for (i=0;i<NN-1;i++) scanf("%d%d",&SS[i],&DD[i]);
      |                       ~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccDJpQAz.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc1hEeEy.o:traffic.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status