[LeetCode] Problem 557 - Reverse Words in a String III

Posted on | In ,

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

Example

Input: “Let’s take LeetCode contest”

Output: “s’teL ekat edoCteeL tsetnoc”

Note

In the string, each word is separated by single space and there will not be any extra space in the string.

Code

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
public String reverseWords(String s) {
    char[] str = s.toCharArray();

    for (int i = 0; i < str.length;) {
        int j = i + 1;

        for (; j < str.length; j++) {
            if (str[j] == ' ')
                break;
        }

        reverse(str, i, j - 1);

        i = j + 1;
    }

    return String.valueOf(str);
}

private void reverse(char[] str, int start, int end) {
    while (start < end) {
        char temp = str[end];
        str[end] = str[start];
        str[start] = temp;

        start++;
        end--;
    }
}