#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define F first
#define S second
#define pb push_back
int cnt[1505];
void initialize(int n);
int hasEdge(int u,int v)
{
if(u<v) swap(u,v);
cnt[u]++;
if(cnt[u]==u) return 1;
else return 0;
}
Compilation message
/tmp/ccN3v8wn.o: In function `main':
grader.cpp:(.text.startup+0x14): undefined reference to `initialize(int)'
collect2: error: ld returned 1 exit status