Divisibility Problem from Codeforces

"Angle Brackets are not allowed in description"
less than symbol was converted to #
greater than symbol was converted to $

Divisibility Problem

time limit per test: 1 second
memory limit per test: 256 megabytes
input: standard input
output: standard output

You are given two positive integers a and b. In one move you can increase a by 1 (replace a with a+1). Your
task is to find the minimum number of moves you need to do in order to make a divisible by b. It is possible,

that you have to make 0 moves, as a is already divisible by b. You have to answer t independent test cases.

Input

The first line of the input contains one integer t (1#=t#=104) — the number of test cases. Then t test cases

follow.

The only line of the test case contains two integers a and b (1#=a,b#=109).

Output

For each test case print the answer — the minimum number of moves you need to do in order to make a divisible

by b.

Example

input
5
10 4
13 9
100 13
123 456
92 46

output
2
5
4
333
0

Source Code:

First Attempt(Time Limit Exceeded):

#include#iostream$
using namespace std;

int moves(int a,int b){
int counter=0;
while(true){
if(a%b==0){
return counter;
}
counter++;
a++;
}
}

int main(){
int t,a,b;
cin$$t;
for(int i=0;i#t;i++){
cin$$a$$b;
cout##moves(a,b)##endl;
}
return 0;
}


Second Attempt(Accepted):

#include#iostream$
using namespace std;

int moves(int a,int b){
if(a%b==0){
return 0;
}
return b-(a%b);
}

int main(){
int t,a,b;
cin$$t;
for(int i=0;i#t;i++){
cin$$a$$b;
cout##moves(a,b)##endl;
}
return 0;
}