LeetCode.14：Longest Common Prefix

最新推荐文章于 2024-09-12 00:15:00 发布

RyanWang0000

最新推荐文章于 2024-09-12 00:15:00 发布

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分类专栏： LeetCode 文章标签： LeetCode

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本文介绍了一种使用双层for循环查找字符串数组中所有元素的最长公共前缀的方法。通过遍历首个元素并检查其是否为数组中其他每个元素的前缀来实现，特别注意了数组可能为空或包含空字符串的情况。

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Write a function to find the longest common prefix string amongst an array of strings.

If there is no common prefix, return an empty string “”.

Example 1:

Input: ["flower","flow","flight"]
Output: "fl"

Example 2:

Input: ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.

Note:

All given inputs are in lowercase letters a-z.

思路：两个for循环，外层遍历第一个元素，内存遍历数组的每一个元素。一定注意特殊情况，例如数组为空，某些数组某个元素为空等等

package com.wanghao;

public class LongestCommonPrefix {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		LongestCommonPrefix lCommonPrefix=new LongestCommonPrefix();
		String string[]= {"dog","racecar","d"};
		System.out.println(lCommonPrefix.longestCommonPrefix(string));
	}
    public String longestCommonPrefix(String[] strs) {
    	int num=0;
    	if (strs == null || strs.length == 0) return "";
    	for (int i = 1; i < strs[0].length(); i++) {
			for (int j = 1; j < strs.length; j++) {
				if (!strs[j].startsWith(strs[0].substring(0, i))) {
					return strs[0].substring(0, num);
				}
			}
			num++;
		}
    	return strs[0].substring(0, num);
    }
}