题解 | #最长公共前缀#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param strs string字符串一维数组 
     * @return string字符串
     */
    public String longestCommonPrefix (String[] strs) {
        // write code here
        if(strs == null || strs.length == 0) {
            return "";
        }
        System.out.println("1xxxxxxxxx");
        String commonPrefix = strs[strs.length-1];
        for(int i = strs.length-2; i>=0; i--) {
            commonPrefix = commonPrefix(commonPrefix, strs[i]);
        }
        return commonPrefix;
    }

    public String commonPrefix(String a, String b) {
        System.out.println("2xxxxxxxxx");
        char[] aArr = a.toCharArray();
        char[] bArr = b.toCharArray();

        int length = Math.min(a.length(), b.length());
        StringBuilder sb = new StringBuilder("");
        for(int i=0; i< length; i++) {
            if(aArr[i] == bArr[i]) {
                sb.append(aArr[i]);
            } else {
                break;
            }
        }
        System.out.println("3xxxxxxxxx");
        return sb.toString();
    }


}