利用把原有时间全变成基础的秒，计算完以后，恢复成时分秒的格式
java
import java.util.Scanner;this
public class MyTime { public static int se = 0; public static int mi = 0; public static int ho = 0; Scanner sc=new Scanner(System.in); public int bian; /*public MyTime(int bian) { super(); this.bian = bian; }*/ public void addSecond() { int se1 = ho * 3600 + mi * 60 + se + bian; ho = se1 / 3600; int mi1 = se1 % 3600; mi = mi1 / 60; se = mi1 % 60; } public void subSecond() { int se1 = ho * 3600 + mi * 60 + se - bian; if (se1 >= 0) { ho = se1 / 3600; int mi1 = se1 % 3600; mi = mi1 / 60; se = mi1 % 60; } else { System.out.println("請正確輸入"); } } public void addMinute() { int mi1 = ho * 60 + mi + bian; ho = mi1 / 60; mi = mi1 % 60; } public void subMinute() { int mi1 = ho * 60 + mi - bian; if (mi1 >= 0) { ho = mi1 / 60; mi = mi1 % 60; } else { System.out.println("請正確輸入"); } } public void addHour() { ho += bian; } public void subHour() { ho -= bian; if (ho < 0) { System.out.println("請正確輸入"); } } public void xuan() { System.out.println("選擇操做的部分："); String xuan1 = sc.next(); switch (xuan1) { case "秒": System.out.println("选择的操做过程"); String xuan2=sc.next(); if(xuan2.equals("加")){ System.out.println("请输入改变量"); bian=sc.nextInt(); addSecond(); }else if(xuan2.equals("减")){ System.out.println("请输入改变量"); bian=sc.nextInt(); subSecond(); }else{ System.out.println("请按要求操做"); } break; case "分": System.out.println("选择的操做过程"); String xuan3=sc.next(); if(xuan3.equals("加")){ System.out.println("请输入改变量"); bian=sc.nextInt(); addMinute(); }else if(xuan3.equals("减")){ System.out.println("请输入改变量"); bian=sc.nextInt(); subMinute(); }else{ System.out.println("请按要求操做"); } break; case "时": System.out.println("选择的操做过程"); String xuan4=sc.next(); if(xuan4.equals("加")){ System.out.println("请输入改变量"); bian=sc.nextInt(); addHour(); }else if(xuan4.equals("减")){ System.out.println("请输入改变量"); bian=sc.nextInt(); subMinute(); }else{ System.out.println("请按要求操做"); } break; default: System.out.println("请按要求操做"); break; } } public void display() { System.out.println("時間為：" + ho + "時" + mi + "分" + se + "秒"); } public static void main(String[] args) { MyTime mt=new MyTime(); mt.xuan(); mt.display(); } }