CodeMarshal - Prime Queries

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
bitset<100010>ck;
vector<int>prime;
void sieve(int z)
{
    ll i,j,k;
    int x=z+1;
    ck.set();
    ck[0]=ck[1]=0;
    for(i=2;i<3;i++){
        for(j=2*2;j<=x;j+=2)ck[j]=0;
        prime.push_back(i);
    }
    for(;i<=x;i+=2)if(ck[i]){
        for(j=i*i,k=2*i;j<=x;j+=k)ck[j]=0;
        prime.push_back(i);
    }
}
int main()
{
    sieve(1e5);
    int i,j,t,x,y,p_cnt;
    bool k;
    ll re;
    scanf("%d",&t);
    while(t--){
        scanf("%d %d",&x,&y);
        for(i=j=1,re=k=p_cnt=0;i<x;){
            while(p_cnt!=y+1&&j<=x){
                if(j==x)k=true;
                if(ck[j])p_cnt++;
                j++;
            }
            while(k||p_cnt!=y&&i<x){
                if(k&&p_cnt<=y)re+=(j-i);
                else re+=(j-i-1);
                if(ck[i])p_cnt--;
                i++;
                if(i==x)k=false;
            }
        }
        printf("%lld\n",re+1);
    }
    return 0;
}