c++ - Reversing order of words in a sentence

Question

#include <iostream>
#include <cstring>
using namespace std;
void reverse(char* sentence)
{
    int index = strlen(sentence) - 1;
    char last = '';
    int hold = 0;
    while ( index != 0){
        while (sentence[index] != ' ')
            index--;
        hold = index; //keeps the index of whitespace
        while (sentence[index] != last){
            cout << sentence[index]; //printing till it either hits end character or whitespace.
            index++;
        }
        last = sentence[hold]; //Keeps the whitespace
        index = hold; //
    }

}
int main()
{
    char* sentence = new char[256];
    cin.getline(sentence, 256);
    reverse(sentence);
}

I want to reverse the orders of words in a sentence and you can see my attempt above.

Sample intput and output should be like this:

Howdy Mr. Mcfly? 

Mcfly? Mr. Howdy

Where i get:

Howdy Mr. Mcfly?
 Mcfly?

There are many similar questions around the internet but what i want is to find error in my own code.

Answer 1

You can use std::string std::vector and std::reverse to make things easier:

std::string sentence = "Your sentence which contains ten words, two of them numbers";
std::stringstream stream(sentence);
std::vector<std::string> words;
for ( std::string word; stream >> word; )
{
    words.push_back(word);
}

Now you have everything separated into words. You may now want to remove question marks or other punctuation, since the logic will be easier to implement while the words are still in the correct order. For reversing, do this:

std::reverse(words.begin(), word.end());

You'll need to include several headers:

#include <string> // for storing strings in a C++ way
#include <sstream> // to easily separate sentences into words
#include <vector> // to dynamically store arbitrary amounts of words
#include <algorithm> // for std::reverse

You can see this code in action with this demo on ideone.com