[LeetCode]--58. Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ’ ‘, return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

For example, Given s = “Hello World”, return 5.

我利用java的库函数，split做的。

public int lengthOfLastWord(String s) { if (s == null || s.length() == 0) return 0; String[] strs = s.split(" "); if (strs.length == 0) return 0; int len = strs[strs.length - 1].length(); if (len > 0) return len; else return 0; }

能通过，如果不能库函数呢，那就用字符数组来检测，从后往前。

public int lengthOfLastWord(String s) { int length = 0; char[] chars = s.toCharArray(); for (int i = s.length() - 1; i >= 0; i--) { if (length == 0) { if (chars[i] == ' ') { continue; } else { length++; } } else { if (chars[i] == ' ') { break; } else { length++; } } } return length; }