How to use an array with a string - c++

Question

I'm creating a program that takes in a sentence or a paragraph. It then asks the user what they'd like to do.
- Covert to all caps
- Covert to all lowercase
- Delete white spaces
- Split words and remove duplicates
- Search for a word in the string
I got the all of them but I can't figure out how to split the words and remove duplicates..
When the 4th choice (“Split Words”) is selected, the words should be put into an array or a structure and each word should be displayed with a loop. After this, duplicate removal should be performed and the program must determine the duplicate words and eliminate them. After this, the word list should be printed again.
Any help with this would be greatly appreciated. Thank you
This is my code & I need help with case 'D'
#include <iostream>
#include <cmath>
#include <cstdlib>
#include <string>
#include <algorithm>
#include <cctype>
using namespace std;
int main() {
string s;
char selection;
string w;
cout << "Enter a paragraph or a sentence : ";
getline(cin, s);
int sizeOfString = s.length();
//cout << "The paragraph has " << sizeOfString << " characters. " << endl; ***Dummy call to see if size works.
//cout << "You entered " << s << endl; *** Dummy function !!
cout << "" << endl;
cout << " Menu " << endl;
cout << " ------------------------" << endl;
cout << "" << endl;
cout << "A -- Convert paragraph to all caps " << endl;
cout << "B -- Convert paragraph to all lowercase " << endl;
cout << "C -- Delete whitespaces " << endl;
cout << "D -- Split words & remove duplicates " << endl;
cout << "E -- Search a certain word " << endl;
cout << "" << endl;
cout << "Please select one of the above: ";
cin >> selection;
cout << "" << endl;
switch (selection) //Switch statement
{
case 'a':
case 'A':
cout << "You chose to convert the paragraph to all uppercase" << endl;
cout << "" << endl;
for (int i = 0; s[i] != '\0'; i++) {
s[i] = toupper(s[i]);
}
cout << "This is it: " << s << endl;
break;
case 'b':
case 'B':
cout << "You chose to convert the paragragh to all lowercase" << endl;
cout << "" << endl;
for (int i = 0; s[i] != '\0'; i++) {
s[i] = tolower(s[i]);
}
cout << "This is it: " << s << endl;
break;
case 'c':
case 'C':
cout << "You chose to delete the whitespaces in the paragraph" << endl;
cout << "" << endl;
for (int i = 0; i < s.length(); i++) {
if (s[i] == ' ')
s.erase(i, 1);
}
cout << "This is it: " << s << endl;
break;
case 'd':
case 'D':
cout << "You chose to split the words & remove the duplicates in the paragraph" << endl;
cout << "" << endl;
case 'e':
case 'E':
cout << "You chose to search for a certain word in the paragraph. " << endl;
cout << "" << endl;
cout << "Enter the word you want to search for: ";
cin >> w;
s.find(w);
if (s.find(w) != std::string::npos) {
cout << w << " was found in the paragraph. " << endl;
} else {
cout << w << " was not found in the paragraph. " << endl;
}
}
return 0;
}

Answer 1

You can use stringstream to split your string by whitespaces and set<string> to contain only unique words. Then your code should look like:
case 'D':
{
cout << "You chose to split the words & remove the duplicates in the paragraph" << endl;
string buf;
stringstream ss(s); // Insert the string into a stream
set<string> tokens; // Create vector to hold our words
while (ss >> buf)
tokens.insert(buf);
cout << "This is it: " << endl;
for (set<string>::iterator it = tokens.begin(); it != tokens.end(); ++it) {
cout << *it << " ";
}
cout << endl;
break;
}