package com.jonkey.test;

import java.math.BigInteger;

public class Test6 {

/**

• @param args
• 需求:求出1000的阶乘所有零和尾部零的个数,不用递归做
  /
  public static void main(String[] args) {
  /int result = 1;
  for(int i = 1; i <= 1000; i++) {
  result = result * i;
  }

System.out.println(result); //因为1000的阶乘远远超出了int的取值范围

*///demo1();demo2();}

public static void demo2() { //获取1000的阶乘尾部有多少个零

BigInteger bi1 = new BigInteger("1");for(int i = 1; i <= 1000; i++) { BigInteger bi2 = new BigInteger(i+"");bi1 = bi1.multiply(bi2); //将bi1与bi2相乘的结果赋值给bi1}String str = bi1.toString(); //获取字符串表现形式StringBuilder sb = new StringBuilder(str);str = sb.reverse().toString(); //链式编程

int count = 0; //定义计数器

for(int i = 0; i < str.length(); i++) { if('0' != str.charAt(i)) { break;}else { count++;}}

System.out.println(count);

}

public static void demo1() { //求1000的阶乘中所有的零

BigInteger bi1 = new BigInteger("1");for(int i = 1; i <= 1000; i++) { BigInteger bi2 = new BigInteger(i+"");bi1 = bi1.multiply(bi2); //将bi1与bi2相乘的结果赋值给bi1}String str = bi1.toString(); //获取字符串表现形式int count = 0;for(int i = 0; i < str.length(); i++) { if('0' == str.charAt(i)) { //如果字符串中出现了0字符count++; //计数器加1}}System.out.println(count);}

}

String[] arr1 = new String[4];

arr1[0]="hong";arr1[1]="hei";arr1[2]="hua";arr1[3]="p";

int[] arr2 = new int[13];

for (int i = 0; i < 4; i++) { for (int j = 0; j < 13; j++) { arr2[j] = j+1;

System.out.println(""+arr1[i]+arr2[j]);

}