HDU - 1496 Equations

Consider equations having the following form:

a*x1^2+b*x2^2+c*x3^2+d*x4^2=0
a, b, c, d are integers from the interval [-50,50] and any of them cannot be 0.

It is consider a solution a system ( x1,x2,x3,x4 ) that verifies the equation, xi is an integer from [-100,100] and xi != 0, any i ∈{1,2,3,4}.

Determine how many solutions satisfy the given equation.
InputThe input consists of several test cases. Each test case consists of a single line containing the 4 coefficients a, b, c, d, separated by one or more blanks.
End of file.OutputFor each test case, output a single line containing the number of the solutions.
Sample Input

1 2 3 -4
1 1 1 1

Sample Output

39088
0

#include<iostream>
#include<cstdio>
#include<cstring>

using namespace std;

int he[2000005],ji[105];

int main()
{
    for(int i=1;i<=100;i++)
        ji[i]=i*i;
    int a,b,c,d;
    while(~scanf("%d %d %d %d",&a,&b,&c,&d))
    {
        memset(he,0,sizeof(he));
        int sum=0;
        for(int i=1;i<=100;i++)
            for(int j=1;j<=100;j++)
                he[a*ji[i]+b*ji[j]+1000000]++;
        for(int i=1;i<=100;i++)
            for(int j=1;j<=100;j++)
                sum+=he[-(c*ji[i]+d*ji[j])+1000000];
        printf("%d\n",sum*16);
    }
    
    
    return 0;    
}