A10803. Success Rate
编程题
普及/提高-
知识点
题目描述
You are an experienced Codeforces user. Today you found out that during your activity on Codeforces you have made $y$ submissions, out of which $x$ have been successful. Thus, your current success rate on Codeforces is equal to $x/y$ .
Your favorite rational number in the $[0;1]$ range is $p/q$ . Now you wonder: what is the smallest number of submissions you have to make if you want your success rate to be $p/q$ ?
Your favorite rational number in the $[0;1]$ range is $p/q$ . Now you wonder: what is the smallest number of submissions you have to make if you want your success rate to be $p/q$ ?
输入格式
The first line contains a single integer $t$ ( $1<=t<=1000$ ) — the number of test cases.
Each of the next $t$ lines contains four integers $x$ , $y$ , $p$ and $q$ ( $0<=x<=y<=10^{9}$ ; $0<=p<=q<=10^{9}$ ; $y>0$ ; $q>0$ ).
It is guaranteed that $p/q$ is an irreducible fraction.
Hacks. For hacks, an additional constraint of $t<=5$ must be met.
Each of the next $t$ lines contains four integers $x$ , $y$ , $p$ and $q$ ( $0<=x<=y<=10^{9}$ ; $0<=p<=q<=10^{9}$ ; $y>0$ ; $q>0$ ).
It is guaranteed that $p/q$ is an irreducible fraction.
Hacks. For hacks, an additional constraint of $t<=5$ must be met.
输出格式
For each test case, output a single integer equal to the smallest number of submissions you have to make if you want your success rate to be equal to your favorite rational number, or -1 if this is impossible to achieve.
输入输出样例
输入 #1
4 3 10 1 2 7 14 3 8 20 70 2 7 5 6 1 1
输出 #1
4 10 0 -1
说明/提示
In the first example, you have to make 4 successful submissions. Your success rate will be equal to $7/14$ , or $1/2$ .
In the second example, you have to make 2 successful and 8 unsuccessful submissions. Your success rate will be equal to $9/24$ , or $3/8$ .
In the third example, there is no need to make any new submissions. Your success rate is already equal to $20/70$ , or $2/7$ .
In the fourth example, the only unsuccessful submission breaks your hopes of having the success rate equal to 1.
In the second example, you have to make 2 successful and 8 unsuccessful submissions. Your success rate will be equal to $9/24$ , or $3/8$ .
In the third example, there is no need to make any new submissions. Your success rate is already equal to $20/70$ , or $2/7$ .
In the fourth example, the only unsuccessful submission breaks your hopes of having the success rate equal to 1.