[LeetCode]14. Longest Common Prefix

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

寻找一组字符串中的最大公共字符串

#include<iostream>
#include<string>
#include<vector>
using namespace std;
class Solution {
public:
	string longestCommonPrefix(vector<string> &strs) {
		int n = strs.size();
		string res;
		if (n == 0)return res;
		for (int pos = 0; pos < strs[0].size(); pos++)//最长前缀的长度不超过strs[0].size()，逐个字符的比较
		{
			for (int k = 1; k < n; k++)//strs[0]的第pos个字符分别和strs[1...n-1]的第pos个字符比较
			{
				if (strs[k].size() == pos || strs[k][pos] != strs[0][pos])
					return res;
			}
			res.push_back(strs[0][pos]);
		}
		return res;
	}
};