c++ - Ruby Program : Trailing zeros in the nth Power of a numbers factorial -

i trying port c++ code ruby. running script gives me "execution timed out" error.

this ruby code:

t = gets.to_i t.times     = gets.to_i     b = gets.to_i     c = 0     j = 5     until j <=       j*5       c += a/j     end      puts c*b end 

this c++ code:

#include<iostream>  main() {   long t, a, b, = 0, j, c;    std::cin >> t;   for( ; < t ; i++)   {     std::cin >> >> b;     c = 0;     for( j = 5 ; j <= ; j *= 5)        c += a/j;     std::cout << c * b << '\n';   } } 

my input is:

2 100 10 5 4 

any output is:

240 4 

there 2 test-cases:

1. the number of zeroes trailing in (100!)^10
2. the number of zeroes trailing in (5!)^4

i write calculation in ruby this:

a = 100 b = 10 ((1..a).inject(:*)**b).to_s[/0*$/].size #=> 240 

where (1..a).inject(:*) calculates a!, **b exponential function, to_s translates number string, [/0*$/] extracts trailing zeros und size counts them...