Word Count with Sorting C++

Question

This is a question I have for my Data Structure class. I have completely no idea in dealing with it, can anyone give some hints please?

1. How to stop the program and ensure the output can be out correctly?
2. Whether I have to deal with the mapping?

the question paper I had from the professor

The following is my coding example:

#include <iostream>
#include <string>

using namespace std;

int main()
{
    string s [100];

    for (int i = 0; i < 100; i++) {
        cin >> s[i];
        s[i] = Sort(s[i], s[i+1]);
    }


    //check the number of time the words repeatcout the answer
    for (int i = 0; i < 100; i++) {
        cout << s[i] << count (s[i],s[i+1]) <<endl;
    }
    return 0;
}


string Sort(string current, string next ) {
    if (current > next) {
        string temp = current;
        current = next;
        next = temp;
    }
    else {
        return current;
    }
}

int count(string word, string Nextword) {
    int count;
    if (word == Nextword) {
        count++;
    }
    else {
        return count;
    }
}

Answer 1

std::map can do sorting and counting at the same time for you:

#include <map>
#include <iostream>
using std::cin;
using std::cout;
using std::endl;
using std::string;

int main() {
  std::map<string,size_t> wordcount;
  for(string word;cin>>word;++wordcount[word]);
  for(auto it=wordcount.begin();it!=wordcount.end();++it)
    cout << it->first << " " << it->second << endl;
}

echo -ne "Computer system\ncomputer design\nalgorithm design and analysis\nquantum computer\ncomputer science department" | ./a.out
Computer 1
algorithm 1
analysis 1
and 1
computer 3
department 1
design 2
quantum 1
science 1
system 1