Given a sequence of words, print all anagrams together

// A C program to print all anagarms together #include <stdio.h> #include <stdlib.h> #include <string.h>   // structure for each word of duplicate array struct Word {     char* str;  // to store word itself     int index; // index of the word in the original array };   // structure to represent duplicate array. struct DupArray {     struct Word* array;  // Array of words     int size;   // Size of array };   // Create a DupArray object that contains an array of Words struct DupArray* createDupArray(char* str[], int size) {     // Allocate memory for dupArray and all members of it     struct DupArray* dupArray =               (struct DupArray*) malloc( sizeof(struct DupArray) );     dupArray->size = size;     dupArray->array =       (struct Word*) malloc( dupArray->size * sizeof(struct Word) );       // One by one copy words from the given wordArray to dupArray     int i;     for (i = 0; i < size; ++i)     {         dupArray->array[i].index = i;         dupArray->array[i].str = (char*) malloc( strlen(str[i]) + 1 );         strcpy(dupArray->array[i].str, str[i] );     }       return dupArray; }   // Compare two characters. Used in qsort() for sorting an array of // characters (Word) int compChar(const void* a, const void* b) {     return *(char*)a - *(char*)b; }   // Compare two words. Used in qsort() for sorting an array of words int compStr(const void* a, const void* b) {     struct Word* a1 = (struct Word *)a;     struct Word* b1 = (struct Word *)b;     return strcmp(a1->str, b1->str); }   // Given a list of words in wordArr[], void printAnagramsTogether(char* wordArr[], int size) {     // Step 1: Create a copy of all words present in given wordArr.     // The copy will also have orignal indexes of words     struct DupArray* dupArray = createDupArray(wordArr, size);       // Step 2: Iterate through all words in dupArray and sort     // individual words.     int i;     for (i = 0; i < size; ++i)        qsort(dupArray->array[i].str,              strlen(dupArray->array[i].str), sizeof(char), compChar);       // Step 3: Now sort the array of words in dupArray     qsort(dupArray->array, size, sizeof(dupArray->array[0]), compStr);       // Step 4: Now all words in dupArray are together, but these     // words are changed. Use the index member of word struct to     // get the corresponding original word     for (i = 0; i < size; ++i)         printf("%s ", wordArr[dupArray->array[i].index]); }   // Driver program to test above functions int main() {     char* wordArr[] = {"cat", "dog", "tac", "god", "act"};     int size = sizeof(wordArr) / sizeof(wordArr[0]);     printAnagramsTogether(wordArr, size);     return 0; }

Output:

act tac cat god dog