Witch game

input/code.cpp: In function 'void processheavy(int)':
input/code.cpp:42:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < e.size(); i++)
                            ^
input/code.cpp: In function 'void processlight(int, int)':
input/code.cpp:70:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < ad[u].size(); i++)
                                ^
input/code.cpp: In function 'int main()':
input/code.cpp:113:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < e.size(); i++)
                            ^

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key

typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;
typedef set<int>::iterator sit;
typedef map<int,int>::iterator mit;
typedef vector<int>::iterator vit;

ll d[100001];
set<int> adj[100001];
set<ii> edges;
vi ad[100001];
const int C = 450;
ll ansheavy;
ll anslight;


bool heavy(int u)
{
	if(ad[u].size() >= C) return true;
	return false;
}
vector<ii> e;

void processheavy(int x)
{
	for(int i = 0; i < e.size(); i++)
	{
		int heavycnt = 1;
		int u = e[i].fi; int v = e[i].se;
		if(u==x||v==x) continue;
		if(adj[x].find(u)==adj[x].end()) continue;
		if(adj[x].find(v)==adj[x].end()) continue;
		if(heavy(u)) heavycnt++;
		if(heavy(v)) heavycnt++;
		{
			if(heavycnt==3)
			{
				ansheavy+=2;
			}
			else if(heavycnt==2)
			{
				ansheavy+=3;
			}
			else
			{
				ansheavy+=6;
			}
		}
	}	
}

void processlight(int u, int v)
{
	for(int i = 0; i < ad[u].size(); i++)
	{
		int w = ad[u][i];
		if(adj[v].find(w)==adj[v].end()) continue;
		if(heavy(w)) continue;
		anslight++;	
	}
}

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	ll n; cin>>n;
	for(int i = 0; i < n; i++)
	{
		int u; cin>>u;
		u--;
		adj[u].insert(i);
		adj[i].insert(u);
		edges.insert(mp(i,u));
		edges.insert(mp(u,i));
		//assert(u!=i);
	}
	ll ans = (n*(n-1)*(n-2))/6;
	ll ee = int(edges.size())/2;
	ans -= ee*(n-2);
	for(int i = 0; i < n; i++)
	{
		ans+=(adj[i].size()*(int(adj[i].size()) -1))/2;
	}
	for(set<ii>::iterator it = edges.begin(); it != edges.end(); it++)
	{
		ad[it->fi].pb(it->se);
		//cerr<<it->fi<<' '<<it->se<<'\n';
		e.pb(mp(it->fi,it->se));
	}
	for(int i = 0; i < n; i++)
	{
		if(heavy(i))
		{
			processheavy(i);
		}
	}
	for(int i = 0; i < e.size(); i++)
	{
		int u = e[i].fi; int v = e[i].se;
		if(heavy(u)||heavy(v)) continue;
		processlight(u,v);
	}
	ansheavy/=12;
	anslight/=6;
	ans-=ansheavy;
	ans-=anslight;
	cout<<ans;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED