Goldbach's Conjecture

#include<stdio.h>
#include<string.h>
#include<math.h>
int mx = 10000005;
bool stat[10000005];
void sieve()
{
    int i,j,sq=sqrt(mx);
    for(i=4;i<=mx;i+=2)stat[i]=1;

    for(i=3;i<=sq;i+=2)
    {
        if(stat[i]==0)
        {
            for(j=i*i;j<=mx;j+=2*i)stat[j]=1;
        }
    }
}

int main()
{
    sieve();
    int k=0;
    int n,t;
    scanf("%d",&t);
    while(t--)
    {
        k++;
        scanf("%d",&n);
        int x,i,flag=0;
        for(i=2;i<=n/2;i++)
        {
            x = n - i;
            if(i>x)
            {
                break;
            }
            if(stat[x]==0 && stat[i]==0)
            {
                flag++;
                //printf("%d = %d + %d\n",n,i,x);
                //break;
            }
        }
        printf("Case %d: %d\n",k,flag);
        /*if(flag==0)
        {
            printf("Goldbach's conjecture is wrong.\n");
        }*/
    }
}