leetcode--最长公共前缀--简单的字符串操作

【题目】：

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

点击打开链接

【答案】：

class Solution {
public:
	string longestCommonPrefix(vector<string>& strs) {
	    	if (strs.empty()) return "";//看来以后写程序，一定要考虑好细节，防止出一些边界上的错误
	    
		string str_result = "";
		string str0 = strs[0];
		int i = 0;
		int len = str0.length();

		while (i<len)
		{
			if (str0.length()<(i + 1)) break;

			char singleChar = str0[i];
			bool flag = true;
			for (auto iterVector = strs.cbegin(); iterVector != strs.cend(); ++iterVector)
			{
				if ((*iterVector).length()<(i + 1) || (*iterVector)[i] != singleChar)
				{
					flag = false;
					break;
				}
			}

			if (flag == false)
			{
				break;
			}
			else
			{
				i++;
			}
		}

		if (i == 0)
		{
			return str_result;
		}
		else
		{
			str_result = str0.substr(0, i);
			return str_result;
		}
	}
};