第五章第五十一题（最长的共同前缀）(Longest common prefix)

*5.51（最长的共同前缀）编写一个程序，提示用户输入两个字符串，显示两个字符串最长的共同前缀。

下面是运行示例：
Enter the first string: Welcome to C++
Enter the second string: Welcome to programming
The common prefix is Welcome to
Enter the first string: Atlanta
Enter the second string: Macon
Atlanta and Macon have no common prefix

*5.51(Longest common prefix) Write a program that prompts the user to enter two strings and displays the largest common prefix of the two strings.

Here are some sample runs:
Enter the first string: Welcome to C++
Enter the second string: Welcome to programming
The common prefix is Welcome to
Enter the first string: Atlanta
Enter the second string: Macon
Atlanta and Macon have no common prefix

下面是参考答案代码:

import java.util.*;

public class LongestCommonPrefixQuestion51 {
  public static void main(String[] args) {
    int lengthUserString1, lengthUserString2;
    String userString1, userString2, prefixString = "";

    Scanner inputScanner = new Scanner(System.in);

    System.out.print("Enter the first string: ");
    userString1 = inputScanner.nextLine();
    lengthUserString1 = userString1.length();

    System.out.print("Enter the second string: ");
    userString2 = inputScanner.nextLine();
    lengthUserString2 = userString1.length();

    for (int strIndex = 0; strIndex < (lengthUserString1 > lengthUserString2 ? lengthUserString2
        : lengthUserString1); strIndex++) {
      if (userString1.charAt(strIndex) == userString2.charAt(strIndex)) {
        prefixString += userString1.charAt(strIndex);
        continue;
      }
      break;
    }

    if (prefixString.length() != 0)
      System.out.println("The common prefix is " + prefixString);
    else
      System.out.printf("%s and %s have no common prefix", userString1, userString2);

    inputScanner.close();
  }
}

运行效果：

注：编写程序要养成良好习惯
1.文件名要用英文，具体一点
2.注释要英文
3.变量命名要具体，不要抽象（如:a,b,c等等），形式要驼峰化
4.整体书写风格要统一（不要这里是驼峰，那里是下划线，这里的逻辑段落空三行，那里相同的逻辑段落空5行等等）
5.普通变量，方法名要小驼峰，类名要大驼峰，常量要使用全部大写加上下划线命名法
6.要学习相应的代码编辑器的一些常用快捷键，如：快速对齐等等