import java.util.Scanner; public class Test1_16_6 { public static void main(String[] args) { Scanner in=new Scanner(System.in); for(int j=0;j<3;j++){ System.out.println("请输入用户名"); String user=in.next(); System.out.println("请输入用户密码"); String password=in.next(); if(user.equals("zs")&&password.equals("12345")){ System.out.println("成功登陆"); while(true){ System.out.println("1.打印菱形"); System.out.println("2.打印正方形"); System.out.println("3.打印等边三角形"); System.out.println("4.打印等腰三角形"); System.out.println("5.打印直角三角形"); System.out.println("0.退出程序"); System.out.println("请选择要执行的功能(0-5)"); String num=in.next(); switch(num){ case "1": int no=1; int k=0; for (int i = 0; i < 5; i++) { if(i<3){ for(int l=3-i;l>1;l--){ System.out.print(" "); } for(int l=1;l<=i+no;l++){ System.out.print("* "); } }else{ for(int l=i-2;l>=1;l--){ System.out.print(" "); } for(int l=1;l<=i-k;l++){ System.out.print("* "); } k+=3; } no++; System.out.println(); } break; case "2": for (int i = 0; i < 4; i++) { for (int l = 0; l < 4; l++) { System.out.print("* "); } System.out.println(); } break; case "3": int n=1; for (int i = 0; i < 4; i++) { for (int l =4-i; l > 1; l--) { System.out.print(" "); } for (int l = 1; l <= i+n; l++) { System.out.print("* "); } n++; System.out.println(); } break; case "4": for (int i = 0; i < 4; i++) { for (int l = 0; l < 4-i; l++) { System.out.print("* "); } System.out.println(); } break; case "5": for (int i = 0; i < 4; i++) { for (int l = 0; l <= i; l++) { System.out.print("*"); } System.out.println(); } break; case "0": System.out.println("退出程序"); System.exit(0); default: System.out.println("错误的输入,请重新输入!"); } break; } }else if(j<2){ System.out.println("账户或者密码输入错误请,重新输入(你还有"+(2-j)+"次机会"); }else{ System.out.println("退出程序"); } } } }