leetcode解题之14# Longest Common Prefix Java版 两种方法实现

14. Longest Common Prefix

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

public String longestCommonPrefix2(String[] strs) { if (strs.length == 0) return ""; String prefix = strs[0]; for (int i = 1; i < strs.length; i++) { //取长度短，避免越界，substring 是前闭后开 if (prefix.length() > strs[i].length()) prefix = prefix.substring(0, strs[i].length()); for (int j = 0; j < prefix.length(); j++) if (prefix.charAt(j) != strs[i].charAt(j)) { prefix = prefix.substring(0, j); break; } } return prefix; } public String longestCommonPrefix(String[] strs) { if (strs.length == 0) return ""; String prefix = strs[0]; for (int i = 0; i < strs.length; i++) { // 不等于0 说明，不是从第一个字母开始，prefix长度减去1 while (strs[i].indexOf(prefix) != 0) prefix = prefix.substring(0, prefix.length() - 1); } return prefix; }