【LeetCode】 Longest Common Prefix 【Python || C++】_longest common prefix c++-优快云博客

本文介绍了一种在字符串数组中查找最长公共前缀的方法，通过C++和Python代码实现，展示了如何比较每个字符串的字符来确定共同的起始部分。

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题目：

最长的前缀公共子字符串

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.

#C++版本
class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string b="";
        int i=0,flag=1,j=0;
        if(strs.size()==0){
            return "";
        }
        while(flag==1){
            for(j=0;j<strs.size();j++){
                if(strs[j].size()==0){
                    return "";
                }
                if(strs[j][i]==strs[0][i] && i<strs[j].size()){
                    continue;
                }else{
                    flag=0;
                    break;
                }
            }
            if(j==strs.size()){
                b+=strs[0][i];
            }
            i++;
        }
        return b;
        
    }
};

#Python 版本
class Solution:
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        flag=1
        i=0
        
        if len(strs)==0:
            return ""
        while flag==1:
            j=0
            while(j<len(strs)):
                if len(strs[j])==0:
                    return ""
                print(i,j)
                if i<len(strs[j]) and strs[j][i]==strs[0][i] : 
                    j+=1
                    continue
                else:
                    flag=0
                    break
            if j==len(strs):
                i+=1
        return strs[0][:i]