1.打印菱形
public class T1 {
public static void main(String[] args) {
// TODO Auto-generated method stub
int leng = 6;
int leng1 = leng-1;
System.out.println("空心菱形：");
for(int k = 1;k <= leng;k++){
for(int i = 1;i <= (leng - k);i++){
System.out.print(" ");
}
System.out.print("*");
for(int i = 1;i <= ( (k - 2) * 2 + 1);i++){
System.out.print(" ");
}
if(k != 1){
System.out.print("*");
}
System.out.println();
}
for(int k = leng1;k >=1;k--){
for(int i = 1;i <= (leng - k);i++){
System.out.print(" ");
}
System.out.print("*");
for(int i = 1;i <= ( (k - 2) * 2 + 1);i++){
System.out.print(" ");
}
if(k != 1){
System.out.print("*");
}
System.out.println();
}
int rowNum=11;
System.out.println("实心菱形：");
for(int i = 1;i <= rowNum;i++){
if(i <= rowNum/2 + 1){
for(int k = 1;k <= rowNum/2 + 1- i;k++){
System.out.print(" ");
}
for(int k = 1;k <= i;k++){
System.out.print("* ");
}
System.out.println();
}else{
for(int k =1;k <= (i -(rowNum/2 + 1));k++){
System.out.print(" ");
}
for(int k = 1;k <= (2 *(rowNum/2 + 1) - i);k++){
System.out.print("* ");
}
System.out.println();
}
}
}
}输出结果：
空心菱形：
*
* *
* *
* *
* *
* *
* *
* *
* *
* *
*
实心菱形：
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
* 2.将数字金额转换为大写金额
import java.util.Scanner;
public class ChangeNum {
public static void main(String[] args) {
//String arr[]={"零","壹","贰","叁","肆","伍","陆","柒","捌","玖","拾"};
String arr[]={"零","一","二","三","四","五","六","七","八","九","拾"};
//String a="101";
System.out.println("请输入：");
Scanner input=new Scanner(System.in);
String a=input.next();
input.close();
String ar[]=a.split("");
String stb="";
for(int i=0;i<ar.length;i++){
stb=stb+arr[Integer.parseInt(ar[i])];
}
String stc[]=stb.split("");
switch(ar.length){
case 1:
System.out.println(stc[0]);
break;
case 2:
if(Integer.parseInt(ar[1])==0){
System.out.println(stc[0]+"拾");
}
else{
System.out.println(stc[0]+"拾"+stc[1]);
};
break;
case 3:
if(Integer.parseInt(ar[1])==0){
System.out.println(stc[0]+"佰"+stc[1]+stc[2]);
}
else{
System.out.println(stc[0]+"佰"+stc[1]+"拾"+stc[2]);
};
break;
case 4:
if(Integer.parseInt(ar[1])==0&&Integer.parseInt(ar[2])==0&&Integer.parseInt(ar[3])==0){
System.out.println(stc[0]+"千");
}
else if(Integer.parseInt(ar[1])==0&&Integer.parseInt(ar[2])==0){
System.out.println(stc[0]+"千"+"零"+stc[3]);
}
else if(Integer.parseInt(ar[1])==0&&Integer.parseInt(ar[3])==0){
System.out.println(stc[0]+"千"+stc[1]+stc[2]+"拾");
}
else if(Integer.parseInt(ar[2])==0&&Integer.parseInt(ar[3])==0){
System.out.println(stc[0]+"千"+stc[1]+"佰");
}
else if(Integer.parseInt(ar[1])==0){
System.out.println(stc[0]+"千"+stc[1]+stc[2]+"拾"+stc[3]);
}
else if(Integer.parseInt(ar[3])==0){
System.out.println(stc[0]+"千"+stc[1]+"佰"+stc[2]+"拾");
}
else{
System.out.println(stc[0]+"千"+stc[1]+"佰"+stc[2]+"拾"+stc[3]);
};
break;
default:
break;
}
}
}输出结果：
请输入：
1010
一千零一拾3.将字符串中的汉字、数字和字母分别统计
public class DivideStr {
public static void main(String[] args) {
String str="12ab中文56";
String regex1="[0-9]";
String regex2="[a-zA-Z]";
int count1=0,count2=0,count3=0;
String str1="",str2="",str3="";
String arr[]=str.split("");
for(int i=0;i<arr.length;i++){
if(arr[i].matches(regex1)){
str1=str1+arr[i];
count1++;
}
else if(arr[i].matches(regex2)){
str2=str2+arr[i];
count2++;
}
else{
str3=str3+arr[i];
count3++;
}
}
System.out.println("数字有："+str1+" 共："+count1+"个");
System.out.println("字母有："+str2+" 共："+count2+"个");
System.out.println("汉字有："+str3+" 共："+count3+"个");
}
}
数字有：1256 共：4个
字母有：ab 共：2个
汉字有：中文 共：2个4.计算1+1/（2!）+1/(3!)+…..1/(10!)
public class CountNum {
public static void main(String[] args) {
double sum=0;
double count=1.0;
for(int i=1;i<11;i++){
count=count*i;
sum=sum+1/(count);
}
System.out.println(sum);
}
}输出结果：
1.71828180114638475.台阶问题。青蛙上50级台阶，每次跳一个或者两个台阶。
public class CountTest{
public static long count(int i){
if(i==1){
return 1;
}
if(i==2){
return 2;
}
else{
return count(i-1)+count(i-2);
}
}
public static void main(String args[]){
int n = 50;
long total = count(n);
System.out.println(total);
}
}输出结果：
20365011074