［leetcode#4］Longest Common Prefix

Longest Common Prefix

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

找最长公共字符串。
思路：对字符串进行排序，先让s[0]与s[1]比较出公共前缀，
然后把公共前缀与每个字符串进行比较，得出最长公共前缀

#include <cstring>#include <algorithm>#include <string>#include <vector>using namespace std;class Solution {public:    string Compare(string a, string b) {        int len = a.length();        int len1 = b.length();        len = min(len, len1);        string s = "";        for (int i = 0; i < len; i++) {            if (a[i] != b[i])                break;            else                s += a[i];        }        return s;    }    string longestCommonPrefix(vector<string>& strs) {        sort(strs.begin(), strs.end());        int n = strs.size();        string s = "";        if (n == 0)        return s;        if (n == 1)        return strs[0];        s = Compare(strs[0], strs[1]);        for (int i = 1; i < n-1; i++) {            s = Compare(s, strs[i+1]);        }        return s;    }};