Facebook Hacker Cup Test Round, Almost

Almost

For two integers a and c, we define a and a third integer b to be almost factors of c by choosing the minimal b that minimizes |ab-c|. Your task will be to determine b given a and c.

Input
Your input file will consist of a single integer N, the number of test cases in the file, followed by N pairs of integers a and c. All tokens in the input will be separated by some whitespace.

Output
Your output should consist of N newline-separated integers, each one representing b for the corresponding pair (a, c) in the input.

Constraints
5 ≤ N ≤ 20
1 ≤ a, c ≤ 1010


#include <iostream>
#include <cctype>
#include <cmath>
#include <algorithm>
#include <cstdio>
typedef long unsigned long lli;
using namespace std;

main(){

  int n,i,min;
  lli a[2],b,bef;
 
  cin >> n;
  while(n--){
    cin>>a[0]>>a[1];
    sort(a, a+2);
    bef = 10000000000LL;
    for(i=1,min=1;;i++){
      b=llabs(a[1]-a[0]*(lli)i);
      if(bef>b)bef=b,min=i;
      if(bef<b)break;
    }
    cout<<min<<endl;
    }
}