int diofantic(int n, int s[50001], int a, int b, long long c){
int k = 0; int i = 1; int j = n;
while(i<=n && j>0){
    if(a*s[i]*s[i] + b*s[j]*s[j] == c){
        k++;   //a * x^2 + b*y^2 = c => se trece
         i++;} //ca solutie valida

    if(a*s[i]*s[i] + b*s[j]*s[j] < c)
        i++; //daca ec < c; muta casuta

    if(a*s[i]*s[i] + b*s[j]*s[j] > c)
        j--; //daca ec > c; muta casuta cealalta

} return k;}