字符串操作 —— 14_最长公共前缀

2. 14_最长公共前缀

/*
输入: ["flower","flow","flight"]
输出: "fl"
*/
class Solution {
    public String longestCommonPrefix(String[] strs) {
        if(strs == null || strs.length == 0) return "";
        if(strs.length == 1) return strs[0];
        int k = 0;
        StringBuilder sb = new StringBuilder("");
        while(k < strs[0].length()){
            char c = strs[0].charAt(k);
            int i = 1;
            while(i < strs.length && k < strs[i].length()){
                if(strs[i].charAt(k) == c) i++;
                else return sb.toString();
            }
            if(i < strs.length) return sb.toString();
            sb.append(c);
            k++;
        }
        return sb.toString();
    }
}