Given a sequence of words, print all anagrams together using STL

Given an array of words, print all anagrams together. For example, if the given array is {“cat”, “dog”, “tac”, “god”, “act”}, then output may be “cat tac act dog god”.

Recommended: Please solve it on “PRACTICE” first, before moving on to the solution.

Other approaches are discussed here in these posts
1) given-a-sequence-of-words-print-all-anagrams-together
2) given-a-sequence-of-words-print-all-anagrams-together-set-2

Here is HashMap solution using C++ Standard Template Library.
Approach :
1) Store the vector elements in HashMap with key as the sorted string
2) if key is same, then add string to value of HashMap(string vector)
3) Traverse the HashMap and print the anagram strings

```// CPP program for finding all anagram
// pairs in the given array
#include <iostream>
#include <algorithm>
#include <unordered_map>
#include <vector>
using namespace std;

// utility function for printing anagram list
void printAnagram(unordered_map<string,
vector<string> >& store)
{
unordered_map<string, vector<string> >::iterator it;
for (it = store.begin(); it != store.end(); it++) {
vector<string> temp_vec(it->second);
int size = temp_vec.size();
if (size > 1) {
for (int i = 0; i < size; i++) {
cout << temp_vec[i] << " ";
}
cout << "\n";
}
}
}

// utility function for storing the vector of strings
// into HashMap
void storeInMap(vector<string>& vec)
{
unordered_map<string, vector<string> > store;
for (int i = 0; i < vec.size(); i++) {

string tempString(vec[i]);
sort(tempString.begin(), tempString.end());

// check for sorted string if it already exists
if (store.find(tempString) == store.end()) {
vector<string> temp_vec;
temp_vec.push_back(vec[i]);
store.insert(make_pair(tempString, temp_vec));
}

else {
// push new string to already existing key
vector<string> temp_vec(store[tempString]);
temp_vec.push_back(vec[i]);
store[tempString] = temp_vec;
}
}

// print utility function for printing
// all the anagrams
printAnagram(store);
}

// Driver code
int main()
{
// initialize vector of strings
vector<string> arr;
arr.push_back("geeksquiz");
arr.push_back("geeksforgeeks");
arr.push_back("abcd");
arr.push_back("forgeeksgeeks");
arr.push_back("zuiqkeegs");
arr.push_back("cat");
arr.push_back("act");
arr.push_back("tca");

// utility function for storing strings
// into hashmap
storeInMap(arr);
return 0;
}
```

Note : Compile above program with -std=c++11 flag in g++
Output:

```cat act tca
geeksforgeeks forgeeksgeeks
geeksquiz zuiqkeegs
```

This article is contributed by Mandeep Singh. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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