HDU1496 Equations 卡时间第二题

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<cstdio>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#include<memory>
#include<map>
#include<cstring>
using namespace std;
int a,b,c,d;
int q[4000000];
int main()
{
    int i,j,k,ans;
    while(cin>>a>>b>>c>>d){
        ans=0;
        if(a>0&&b>0&&c>0&&d>0){
          printf("0
");
          continue;
        }
        if(a<0&&b<0&&c<0&&d<0){ 
          printf("0
");
          continue;
        }
        memset(q,0,sizeof(q));
        for(i=1;i<=100;i++)
         for(j=1;j<=100;j++)
           q[i*i*a+j*j*b+1000000]++;
        for(i=1;i<=100;i++)
         for(j=1;j<=100;j++)
           ans+=q[1000000-i*i*c-j*j*d];
        printf("%d
",ans*16);
    }
    return 0;
}
View Code

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#include<memory>
#include<map>
using namespace std;
int a,b,c,d;
map<int,int>q;
int main()
{
    int i,j,k,ans;
    while(cin>>a>>b>>c>>d){
        ans=0;
         if(a>0&&b>0&&c>0&&d>0||a<0&&b<0&&c<0&&d<0)  //因为x那项永远是正数,如果系数都为正或者为负的时候明显不等于0  
        {  
            printf("0
");  
            continue;  
        } 
        q.clear();
        for(i=1;i<=100;i++)
         for(j=1;j<=100;j++)
           q[i*i*a+j*j*b]++;
        for(i=1;i<=100;i++)
         for(j=1;j<=100;j++)
           ans+=q[-i*i*c-j*j*d];
        printf("%d
",ans*16);
    }
    return 0;
}
View Code


 
原文地址:https://www.cnblogs.com/hua-dong/p/7711450.html