Prime visit challenge

#1

sir,my code is not submitting.It is showing time limit exceeded in one case rest all cases are correct.question is of prime visit
link:https://ide.codingblocks.com/s/87214

#2

for prime numbers use Sieve of Eratosthenes

#3

i used this approach but getting incorrect output.What changes it requires?
https://online.codingblocks.com/player/19272/content/7519/4712

#define MAX 1000005
#define ll long long int
bool arr[MAX]={true};
using namespace std;

void sieve()
{
arr[0]=arr[1]={false};
for(ll i=2;ii<=MAX;i++)
{
if(arr[i]==true)
{
for(ll j=2i;j<MAX;j+=i)
arr[j]=false;
}
}
}

#4

this is the code for the prime sieve(optimized)
void primeseive(long long int p[1000000],long long int N)
{
p[0]=p[1]=0;
p[2]=1;
for(long long int i=3;i<N;i=i+2)
{
p[i]=1;
}
for(long long int i=3;i<N;i=i+2)
{
if(p[i])
{
for(long long int j=ii;j<N;j=j+2i)
{
p[j]=0;
}
}
}
return;
}

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