POJ 3006 找给定的一叙述找第n个素数

# include <stdio.h>
# include <math.h>
int judge(int n)
{
    int i,j,leag=1;
    if(n==0 || n==1)
        leag=0;
    else
    {
        if(n==2)
            leag=1;
        else
            for(i=2;i<=sqrt(n);i++)
                if(n%i == 0)
                {
                    leag=0;
                    break;
                }
    }
    return leag;
}
int main()
{
    int a,d,n,i,j,k,t;
    scanf("%d%d%d",&a,&d,&n);
    while(a && d && n)
    {
        while(n)
        {
            if(judge(a))
            {
                n--;
                a=a+d;
            }
            else
                a=a+d;
        }
        printf("%d\n",a-d);
        scanf("%d%d%d",&a,&d,&n);
    }
    return 0;
}