## Saturday, 30 November 2013

### Reverse number logic using integer

Reverse number logic using integer :

public static int reverseNumber(int i)
{
int temp = 0;
while (i > 10)
{
int num = i % 10;
temp = (temp * 10) + num;
i = i / 10;
}
temp = (temp * 10) + i;

return temp;

}

### Find trailing zero of n factorial

Hello,
Here is small logic program to find trailing zero in n factorial. (n > 0). Here we are dividing the passing parameter with power of 5.
e.g .  Take 51.   How many trailing zero for 51 factorial. Let’s start.
Now Take 5  and divide 51 with 5 will ans. = 51/5 = 10  let  save  10 in variable.
Now increase power of 5 = 52  = 25 and divide 51 with 25 = 51/25 = 2.
Now increase power of 5 = 53 = 125.  Now check 51/124  < 0.
so it is not possible more to divide 51.

Here is C# implementation for this logic.

public static double ZeroCnt(int num)
{
int cnt, pow, number;
cnt = 0;
pow = 1;
number = 5;
while (number < num)
{
cnt +=  num / number;
pow ++;
number = Convert.ToInt32(Math.Pow(5, pow));
}
return cnt;
}