Easy Number Challenge

#include<iostream>
#include <cstdlib> 
#include<cmath>
using namespace std;
int aaa[1000001]={0};
int d(int k)
{
    int i,t=0;
    if(aaa[k]!=0)return aaa[k];
    else 
        for(i=1;i<=(int)sqrt((float) k);i++)
        {
            if(k%i==0)
            t+=2;
            if(i*i==k)t--;
        }
    return aaa[k]=t;
}
int main()
{
    int a,b,c,i,j,k,t=0,n;
    cin>>a>>b>>c;
    for(i=1;i<=a;i++)
        for(j=1;j<=b;j++)
            for(k=1;k<=c;k++)
            {
                t+=d(i*j*k);
            }
    cout<<t;
    return 0;
}

http://codeforces.com/contest/236/problem/B