Longest Common Prefix

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

 

这题很简单，直接依次比较即可，代码如下：

class Solution {
public:
    string longestCommonPrefix(vector<string> &strs) {
        if( strs.empty() ) return string();
        size_t len = strs[0].length();
        for(int i=1; i<strs.size(); ++i) {
            len = min(len, strs[i].length());
            int j=0;
            while( j<len && strs[i][j] == strs[0][j] ) ++j;
            len = j;
        }
        return strs[0].substr(0, len);
    }
};