Maximal tourism hackerrank problem

problem url:-https://www.hackerrank.com/contests/rookierank-3/challenges/maximal-tourism

code:--

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    int m;
    cin >> n >> m;
    int id[n+1];
    for(int i=1;i<=n;++i)
    id[i]=i;
    for(int i=0;i<m;i++)
{
int p;
int q;
cin>>p>>q;
if(id[p]!=id[q])
{
int num=id[p];
for(int j=1;j<=n;++j)
if(id[j]==num)
id[j]=id[q];
}
}
int a[100001]={0};
int max_count=0;
for(int i=1;i<=n;++i)
{
++a[id[i]];
max_count=max(max_count,a[id[i]]);
}
cout<<max_count;
return 0;
}