LeetCode-in-Java

557. Reverse Words in a String III

Easy

Given a string s, reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

Example 1:

Input: s = “Let’s take LeetCode contest”

Output: “s’teL ekat edoCteeL tsetnoc”

Example 2:

Input: s = “God Ding”

Output: “doG gniD”

Constraints:

• 1 <= s.length <= 5 * 104
• s contains printable ASCII characters.
• s does not contain any leading or trailing spaces.
• There is at least one word in s.
• All the words in s are separated by a single space.

Solution

public class Solution {
    public String reverseWords(String s) {
        int l;
        int r = 0;
        int len = s.length();
        char[] ch = s.toCharArray();
        for (int i = 0; i <= len; i++) {
            if (i == len || ch[i] == ' ') {
                l = r;
                r = i;
                reverse(ch, l, r - 1);
                r++;
            }
        }
        return new String(ch);
    }

    private void reverse(char[] s, int l, int r) {
        char c;
        while (r > l) {
            c = s[l];
            s[l++] = s[r];
            s[r--] = c;
        }
    }
}

This site is open source. Improve this page.