leetcode/src/reverseWordsInAString/reverseWordsInAString.cpp at master · cobain/leetcode · GitHub

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// Source : https://oj.leetcode.com/problems/reverse-words-in-a-string/

// Author : Hao Chen

// Date : 2014-06-16

/**********************************************************************************

* Given an input string, reverse the string word by word.

* For example,

* Given s = "the sky is blue",

* return "blue is sky the".

* Clarification:

* What constitutes a word?

* A sequence of non-space characters constitutes a word.

* Could the input string contain leading or trailing spaces?

* Yes. However, your reversed string should not contain leading or trailing spaces.

* How about multiple spaces between two words?

* Reduce them to a single space in the reversed string.

**********************************************************************************/

#include <ctype.h>

#include <iostream>

#include <string>

#include <vector>

using namespace std;

void reverseWords(string &s) {

bool wordStart = false;

vector<string> v;

const char *pHead =s.c_str();

const char *pStr, *pBegin, *pEnd;

for (pStr=pHead; *pStr!='\0'; pStr++) {

if (!isspace(*pStr) && wordStart == false){

wordStart = true;

pBegin = pStr;

continue;

}

if(isspace(*pStr) && wordStart==true){

wordStart=false;

pEnd = pStr;

v.insert(v.begin(), s.substr(pBegin-pHead, pEnd-pBegin) );

}

if (wordStart==true){

pEnd = pStr;

v.insert(v.begin(), s.substr(pBegin-pHead, pEnd-pBegin) );

}

if (v.size()>0){

s.clear();

char space=' ';

vector<string>::iterator it;

for (it=v.begin(); it!=v.end(); ++it) {

s = s + *it;

s.push_back(space);

}

s.erase(s.end()-1);

}else{

s.clear();

}

cout << "[" << s << "]" <<endl;

}

main()

{

string s;

reverseWords(s);

s=" ";

reverseWords(s);

s="1 ";

reverseWords(s);

s="love";

reverseWords(s);

s="i love cpp";

reverseWords(s);

}

leetcode/src/reverseWordsInAString/reverseWordsInAString.cpp at master · cobain/leetcode · GitHub

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