14. 最长公共前缀

纵向扫描

class Solution {
    public String longestCommonPrefix(String[] strs) {
        if(strs.length == 0 || strs[0].length() == 0) return "";
        if(strs.length == 1) return strs[0];
        StringBuffer sb = new StringBuffer();
        for(int i = 0;; i++){
            int index = 1;
            if(i == strs[0].length()) break;
            char ch = strs[0].charAt(i);
            while(index < strs.length){
                if(i < strs[index].length() && strs[index].charAt(i) == ch){
                    index++;
                }else break;
            }
            if(index == strs.length){
                sb.append(ch);
            }else break;
        }
        return sb.toString();
    }
}