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[转][LeetCode]Longest Common Prefix ——求字符串的最长公共前缀

题记:

这道题不难但是很有意思,有两种解题思路,可以说一种是横向扫描,一种是纵向扫描。

横向扫描:遍历所有字符串,每次跟当前得出的最长公共前缀串进行对比,不断修正,最后得出最长公共前缀串。

纵向扫描:对所有串,从字符串第0位开始比较,全部相等则继续比较第1,2...n位,直到发生不全部相等的情况,则得出最长公共前缀串。

 

横向扫描算法实现:

//LeetCode_Longest Common Prefix//Written by zhou//2013.11.22class Solution {public:    string longestCommonPrefix(vector<string> &strs) {        // IMPORTANT: Please reset any member data you declared, as        // the same Solution instance will be reused for each test case.                if (strs.size() == 0)          return "";                string prefix = strs[0];        for (int i = 1; i < strs.size(); ++i)        {            if (prefix.length() == 0 || strs[i].length() == 0)               return "";                        int len = prefix.length() < strs[i].length() ? prefix.length() : strs[i].length();                        int j;                        for (j = 0; j < len; ++j)            {                if (prefix[j] != strs[i][j])                    break;            }            prefix = prefix.substr(0,j);                    }                return prefix;    }};


纵向扫描代码实现:

function longestCommonPrefix(strs:Array):String{    if(strs == null || strs.length == 0)return;    for(i:int = 0; i < str[0].length - 1; i++)    {        for(j:int = 0; j < str.length - 1; j++)        {            if(str[i].charAt(j) != str[0].charAt(j))return strs[0].substr(0,j);        }    }    return strs[0];}

 

[转][LeetCode]Longest Common Prefix ——求字符串的最长公共前缀