1 冒泡排序
2 public static void main(String[]args){
3 int[] x={1,24,45,56,6,98,90,3,2,65,3};
4 for (int i = 0; i < x.length-1; i++) {
5 //外循环是轮数
6 for (int j = 0; j < x.length-i-1; j++) {
7 //内循环是次数
8 if(x[j+1]<x[j]){
9 int tem=x[j+1];
10 x[j+1]=x[j];
11 x[j]=tem;
12 }
13 }
14 }
15 for (int i = 0; i < x.length; i++) {
16 System.out.print(x[i]+"\t");
17 }
18 }
19 九九乘法表
20 public static void main(String[]args){
21 for (int i = 1; i < 10; i++) {
22 for (int j = 1; j <=i; j++) {
23 System.out.print(j+"*"+i+"="+j*i+"\t");
24 }System.out.println();
25 }
26 }
27 素 数
28 public static void sum3() {
29 int sum = 0;
30 for (int i = 2; i <= 100; i++) {
31 boolean k = true;
32 for (int j = 2; j < i; j++) {
33 if (i % j == 0) {
34 k = false;
35 break;
36 }
37 }
38 if (k) {
39 System.out.print(" " + i);
40 sum += i;
41 }
42 }
43 System.out.println(" \n=" + sum);
44 }
45 菱 形
46 public static void pattern1() {
47 int ling=50;
48 for (int i = 1; i <= ling; i +=2) {
49 for (int j = 0; j < i; j++) {
50 if(j==0){
51 for (int j2 =ling-1; j2>i; j2-=2) {
52 System.out.print(" ");
53 }
54 }
55 System.out.print("*");
56 }
57 System.out.println();
58 }
59 for (int i = 1; i <= ling; i +=2) {
60 for (int j = i; j < ling-2; j++) {
61 if(j==i){
62 for (int j2 =0; j2<i; j2+=2) {
63 System.out.print(" ");
64 }
65 }
66 System.out.print("*");
67 }
68 System.out.println();
69 }
70 }
71
72 空 心 菱 形
73 public static void pattern1() {
74 int ling=18;
75 for (int i = 1; i <= ling; i +=2) {
76 for (int j = 0; j < i; j++) {
77 if(j==0){
78 for (int j2 =ling-1; j2>i; j2-=2) {
79 System.out.print(" ");
80 }
81 }
82 if(j==i-1||j==0){
83 System.out.print("*");
84 }else{
85 System.out.print(" ");
86 }
87 }
88 System.out.println();
89 }
90 for (int i = 1; i <= ling; i +=2) {
91 for (int j = i; j < ling-2; j++) {
92 if(j==i){
93 for (int j2 =0; j2<i; j2+=2) {
94 System.out.print(" ");
95 }
96 }
97 if(j==i||j==ling-3){
98 System.out.print("*");
99 }else{
100 System.out.print(" ");
101 }
102 }
103 System.out.println();
104 }
105 }
