Looking for a better word replacement program in cpp ,than mine

[srikanth chitturi]

Hi all, I have written a word replacement program in c++. Can anyone write a better solution than this? Because this uses character arrays .

#include <stdio.h>
#include <iostream>
#include <string>

#include <vector>
using namespace std;

int main()
{

string str;

vector<string> a;
vector<string>::iterator it;

char word[40];

cout<<"Please enter something :"<<endl;

gets(word);

int pos;

int length = strlen(word);


// copy the sentence into a vector
for(int i=0;i<length;i++)
{
str.push_back(word[i]);

if(word[i] == ' ' || i == length - 1 )
{
a.push_back(str);
str.clear();
continue;
}

}


cout<<"Please enter another string: "<<endl;

cin>>str;


cout<<"Enter the position to replace the word:"<<endl;
cin>>pos;


it = a.begin();

it = a.erase(it+pos);

it = a.begin();

a.insert(it+pos,str);


for(it = a.begin();it <a.end();it++)
{
cout<<*it<<" ";
}

cout<<endl;

system("pause");

}

[kbw]

I'm not sure what that's meant to be doing, but it doesn't feel quite right.

1. Why are you using a char[40] for a string when you could use std::string? You use string elsewhere, so why not there?

2. Why are you mixing gets and std::cout? Do you realise that std::cin and std::cout are tied?

3. Please the code format tags to format your code.

4. Please describe what the program is supposed to be doing.

[srikanth chitturi]

Output of the program
enter the word : I am a girl
Enter another string : boy
Enter the position to replace the word : 3

I am a boy .

This is the output .

Brief explanation :

I have initially taken the word into a character array and have copied it to a vector<string> , Then I have taken another string.
I have finally taken a position value from the user and have replaced the second word with position value .

[kbw]

1. Read the strings into an ordered collection (like a vector).
2. Use the index to identify the element of the collection to be replaced.
3. Overwrite the indexed element with the new word.
4. Write out the sentence from the collection.

[vlad from moscow]

I already said you in your previous theme how your task can be done simply by using std::istringstream.

s.replace( s.find( source ), source.size(), target );

All what you need is to extract the source word from istringstream.

[JLBorges]

I suppose one shouldn't be just destroying white spaces in the original string.

#include <string>
#include <algorithm>
#include <iostream>

std::string replace( std::string str, std::string::size_type pos,
                     const std::string& replacement )
{
    auto start = str.begin() ;
    while( pos > 0 )
    {
        static const auto isspace = []( char c ) { return std::isspace(c) ; } ;
        static const auto isnotspace = []( char c ) { return !std::isspace(c) ; } ;

        auto f = std::find_if( start, str.end(), isspace ) ;
        start = std::find_if( f, str.end(), isnotspace ) ;
        if( start != str.end() ) --pos ;
        else break ;
    }

    if( start != str.end() )
        str.replace( start, std::find_if( start, str.end(), isspace ), replacement ) ;
    return str ;
}

int main()
{
    std::cout << replace( "I    am \t\t a    girl", 3, "boy" ) << '\n' ;
}

TO DO: Handle punctuation correctly.
"I am - repeat am - a girl."