HDU 4993 Revenge of ex-Euclid(数学题 暴力)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=4993

Problem Description

In arithmetic and computer programming, the extended Euclidean algorithm is an extension to the Euclidean algorithm, which computes, besides the greatest common divisor of integers a and b, the coefficients of Bézout's identity, that is integers x and y such that ax + by = gcd(a, b).
---Wikipedia

Today, ex-Euclid takes revenge on you. You need to calculate how many distinct positive pairs of (x, y) such as ax + by = c for given a, b and c.

 

Input

The first line contains a single integer T, indicating the number of test cases. 

Each test case only contains three integers a, b and c.

[Technical Specification]
1. 1 <= T <= 100
2. 1 <= a, b, c <= 1 000 000

 

Output

For each test case, output the number of valid pairs.

 

Sample Input

21 2 31 1 4

 

Sample Output

13

 

Source

BestCoder Round #9

题意：

寻找ax+by = c有多少组解！

代码如下：

#include <cstdio>#include <cmath>int main(){    int t;    int a,b,c;    scanf("%d",&t);    while(t--)    {        scanf("%d%d%d",&a,&b,&c);        int k=0;        for(int x = 1; x*a < c; x++)        {            if((c-a*x)%b == 0)                k++;        }        printf("%d\n",k);    }    return 0;}