A

#include <iostream>
using namespace std;

int main()
{
    long long n;
    cin>>n;
    if(n%4==0||n%4==3)cout<<0;
    else cout<<1;
    return 0;
}

B

#include<bits/stdc++.h>
using namespace std;
pair<int,int>p[5005];
pair<int,int>p2[5005];
int freq[5005];
int k2,k,n,x;
 
int main()
{
    cin>>n>>k;
    k2=k;
    for(int i=0;i<n;i++)
    {
        cin>>x;
        freq[x]++;
        if(freq[x]>k)
        {
            cout<<"NO\n";
            return 0;
        }
        p[i]=make_pair(x,i);
    }
    sort(p,p+n);
    for(int i=0;i<n;i++)
    {
        p2[i].first 
 
= p[i].second;
        if(k2==0)
            k2=k;
        p2[i].second = k2;
        k2--;
    }
    sort(p2,p2+n);
    cout<<"YES\n";
    for(int i=0;i<n;i++)
    {
        cout<<p2[i].second<<" ";
    }
    cout<<endl;
    return 0;
}

C

#include <bits/stdc++.h>
using
 
 namespace std;
int main()
{
    int n,x,y;
    int ans=0;
    scanf("%d%d%d",&n,&x,&y);
    if(x>y)
    {
        printf("%d\n",n);
        return 0;
    }
    for(int i=0;i<n;i++)
    {
        int t;
        scanf("%d",&t);
        if(t<=x){
            ans++;
        }
    }
    printf("%d\n",ans/2+ans%2);
    return 0;
}

Codeforces #531.div3