最长公共前缀

Write a function to find the longest common prefix string amongst an array of
If there is no common prefix, return an empty string "".
编写一个函数来查找字符串数组中最长的公共前缀字符串。
如果没有公共前缀，则返回空字符串“”。

Example 1:
Input: ["flower","flow","flight"]Output: "fl"
Example 2:
Input: ["dog","racecar","car"]Output: ""Explanation: There is no common prefix among the input strings.

思路：通过字符串匹配判断返回的下标是否为零，为零则截取长度加一的字符串继续匹配，直到返回下标不为零为止。

var longestCommonPrefix = function(strs) {
    var len = strs.length;
    if(strs.length == 0){
        console.log(strs.length)
        return ""
    }else{
        console.log(strs.length)
        var minLen = strs[0].length;
        var count = 0;
        for(let i = 1;i < len;i++){
            if(strs[i].length < minLen){
                minLen = strs[i].length;
            }
        }
        for(let j = 1;j <= minLen;j++){
            let leep = true;
            for(let i = 0;i < len;i++){
                if(strs[i].indexOf(strs[0].slice(0,j)) != 0){
                    leep = false;
                }
            }
            if(leep == true){
                count++;
            }else{
                return strs[0].slice(0,count);
            }
        }
        return strs[0].slice(0,count);
    }
};