struct hash {
        int key;
        int value;
        UT_hash_handle hh;
    };

    struct hash *hashtable = NULL;

    void addToHash(int key, int value)
    {
      struct hash *map;
      //I am using the array elements as hash keys
      HASH_FIND_INT(hashtable, &key, map);

      if(map == NULL)
      {
        map = (struct hash*)malloc(sizeof(struct hash));
        map->key = key;
        HASH_ADD_INT(hashtable, key, map);
      }
      map->value = value;
   }


    struct hash *findInHash(int key)
    {
        struct hash *h;
        HASH_FIND_INT(hashtable, &key, h);
        return h;
    }

    bool containsDuplicate(int* nums, int numsSize) {

        struct hash *hPtr;
        int target = 0;
        hashtable = NULL;
        if((numsSize <= 1) || (nums == 0)) return false;

        int i, index1 = 0;

        for(i = 0; i < numsSize; i++)
        {
            /*The below statement will look if the key is already present in the
              hashtable*/
            hPtr = findInHash(*(nums + i) - target);
            /*If the key is found already, then it look for the value of that
            key. If the value and the current array element is same, then a
            duplicate exist*/
            if(hPtr && hPtr->key == *(nums+i))
               return true;
            addToHash(*(nums + i), i);
        }
        struct hash *temp;
        HASH_ITER(hh, hashtable, hPtr, temp) {free(hPtr);}
        return false;
    }