程序设计C 实验三 题目九 方程式(0300)

Description：

 

Consider equations having the following form: a*x1*x1 + b*x2*x2 + c*x3*x3 + d*x4*x4 = 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.

 

Input：

The 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.

 

Output：

or each test case, output a single line containing the number of the solutions.

 

Sample Input：

 

1 2 3 -4

1 1 1 1

 

 

39088

0

 

 

 

#include<stdio.h>

#include<string.h>

int hash1[1000000] = { 0 }, hash2[1000000] = { 0 };

int main()

{

    int a, b, c, d, sum;

    while (scanf("%d%d%d%d", &a, &b, &c, &d) != EOF)

    {

        int i, j, s;

        memset(hash1, 0, sizeof(hash1));

        memset(hash2, 0, sizeof(hash2));

        if ((a>0 && b>0 && c>0 && d>0) || (a<0 && b<0 && c<0 && d<0))

        {

            printf("0\n");

            continue;

        }

        else

        {

            for (i = 1; i <= 100; i++)

            {

                for (j = 1; j <= 100; j++)

                {

                    s = a*i*i + b*j*j;

                    if (s >= 0)hash1[s]++;

                    else hash2[-s]++;

                }

            }

            sum = 0;

            for (i = 1; i <= 100; i++)

            {

                for (j = 1; j <= 100; j++)

                {

                    s = c*i*i + d*j*j;

                    if (s>0)sum += hash2[s];

                    else sum += hash1[-s];

                }

            }

            printf("%d\n", sum * 16);

        }

    }

    return 0;

}

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