Several questions of the pen

1. Digital (100!) There are ____ a 0 behind.

Analysis:

This problem is implemented in code, but is a large number of problems, but in the written examination the emphasis should be on the construction

1 to 100, a total of 10,20 of 0 for the mantissa,.., 90,100. A common 5,15 with a mantissa of 5,..., 85,95.

A total of 20 numbers make up the mantissa is 0, so at that time I filled out 20.

Ignoring a few special numbers, 100,75,50,25, they are a special number that can make up 100.

So the answer should be 24.

Code Validation:

Import Java.math.biginteger;public class Main {public static void main (string[] argv) {main m = new Main (); M.test ();} public void Test () {BigInteger num = biginteger.valueof (1); int count = 0;for (int i = 1; i <=; ++i) {num = Num.multipl Y (biginteger.valueof (i));} while (true) {if (Num.mod (biginteger.valueof)! = biginteger.valueof (0)) Break;count++;num = Num.divide ( Biginteger.valueof (10));} System.out.println (count);}}

2.

Several questions of the pen