Cinte's Leetcode Record
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剑指 Offer 58 - I. 翻转单词顺序

Posted on Edited on In Disqus:
Symbols count in article: 821 Reading time ≈ 1 mins.

剑指 Offer 58 - I. 翻转单词顺序

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class Solution {
public:
    string reverseWords(string s) {
        if(s.empty())
            return "";
        string ret = "";
        int end = s.size() - 1;
        while(end >= 0 && s[end] == ' ')
            --end;
        if(end < 0)
            return "";
        for(int i = end; i >= -1; --i)
        {
            if(i == -1 || s[i] == ' ')
            {
                ret.append(s.substr(i + 1, end - i));
                while(i >= 0 && s[i] == ' ')
                    --i;
                end = i;
                if(end < 0)
                    break;
                ret.append(" ");
            }
        }
        return ret;
    }
};

T(n) : O(n)

S(n) : O(n)

review

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class Solution {
public:
    string reverseWords(string s) {
        string ret;
        int end = s.size();
        for(int i = s.size() - 1; i >= -1; --i) {
            if(i == -1 || s[i] == ' ') {
                if(i != end - 1)
                    ret += s.substr(i + 1, end - i - 1) + " ";
                end = i;
            }
        }
        ret.pop_back();
        return ret;
    }
};