Prime Number Check

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 #include <stdio.h>

int isprime(int n)

{

    if(n==2 || n==3) return 1;

    if(n==1 || n%2==0 || n%3==0) return 0;

    

    for (int i=5;i<=sqrt(n);i=i+6)

    {

        if(n%i==0 || n%(i+2)==0) return 0;

    }

    return 1;

}


int main()

{

    printf("%d\n",isprime(57));

    printf("%d",isprime(61));

    


    return 0;

}



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