<OJ_Sicily>Greatest Common Divisors

Description
A common divisor for two positive numbers is a number which both numbers are divisible by. It's easy to calculate the greatest common divisor between tow numbers. But your teacher wants to give you a harder task, in this task
you have to find the greatest common divisor d between two integers a and b that is in a given range from low to high (inclusive), i.e. low<=d<=high. It is possible that there is no common divisor in the given range.
Input
The first line contains an integer T (1<=T<=10)- indicating the number of test cases.
For each case, there are four integers a, b, low, high (1<=a,b<=1000,1<=low<=high<=1000) in one line.
题目解释：求解两个数a和b在范围low和high之间的最大公约数。实质就是求a和b的公约数，然后符合该公约数在范围low和high之间是最大的
解题思路：使用一个for循环，从a和b中取较小的数，假如较小数是b，从b开始逐渐减一求得符合要求的值
#include <iostream>
using namespace std;
int main(int argc, const char * argv[]) {
// insert code here...
int T, a, b, low, high;
cin >> T;
while (T > 0) {
cin >> a >> b >> low >> high;
int tmp = 0;
if (a < b) {
tmp = a;
a = b;
b = tmp;
}
bool has_answer = false;
int result = 0;
for (int i = b; i >= 1 ; i--) { // 从小的数开始，逐个找到符合要求的值
if ((b % i) == 0 && (a % i) == 0 && i >= low && i <= high) {
has_answer = true;
result = i;
break;
}
}
if (has_answer) cout << result<< endl;
else cout << "No answer" << endl;
T--;
}
return 0;
}