UVA 12716 GCD XOR

#include<bits/stdc++.h>
#include<iostream>
#include<stdio.h>
#include<cmath>
using namespace std;
 const int ma =30000005;
int ans[30000005];
void solve()
{
    int top=ma >> 1,b;
    for(int c=1;c<=top;++c)
    {
        for(int a=c+c;a<=ma;a+=c){
            b=a-c;
            if((a^b)==c)++ans[a];
        }
    }
    for(int i=2;i<=ma;++i)ans[i]=ans[i-1]+ans[i];
}
int id=1;
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    #endif // ONLINE_JUDGE
    int t;
        solve();
    scanf("%d",&t);
        int num;
    while(t--)
    {
        scanf("%d",&num);
        printf("Case %d: %d
",id++,ans[num]);
    }
}