leetcode 186: Reverse Words in a String II

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Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.

The input string does not contain leading or trailing spaces and the words are always separated by a single space.

For example,
Given s = "the sky is blue",
return "blue is sky the".

Could you do it in-place without allocating extra space?

[思路]

反转整个字符串, 再反转每个单词即可

[注意]

None

[DODE]

public class Solution {
    //the sky is blue
    public void reverseWords(char[] s) {
        //input check
        if(s.length<=1) return;
        
        swap(s, 0, s.length-1);
        
        int i=0, j=1;
        
        while(j<s.length) {
            while(j<s.length && s[j]!=' ') {
                ++j;
            }
            swap(s, i, j-1);
            i = j+1;
            j = i+1;
        }
        
    }
    
    private void swap(char[] s, int i, int j) {
        while(i<j) {
            char temp = s[i];
            s[i] = s[j];
            s[j] = temp;
            ++i;
            --j;
        }
    }
}

leetcode 186: Reverse Words in a String II

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原文地址：http://blog.csdn.net/xudli/article/details/43666783