Sorting Array of Strings in C - Hacker Rank Solution

Hello coders, how is it going!! Today we will be solving Sorting Array of Strings in C Hacker Rank Solution.

Task

To sort a given array of strings into lexicographically increasing order or into an order in which the string with the lowest length appears first, a sorting function with a flag indicating the type of comparison strategy can be written. The disadvantage with doing so is having to rewrite the function for every new comparison strategy.

A better implementation would be to write a sorting function that accepts a pointer to the function that compares each pair of strings. Doing this will mean only passing a pointer to the sorting function with every new comparison strategy.

Given an array of strings, you need to implement a string_sort function which sorts the strings according to a comparison function, i.e, you need to implement the function :

void string_sort(const char **arr,const int cnt, int (*cmp_func)(const char* a, const char* b)){
    
}

The arguments passed to this function are:

• an array of strings : arr
• length of string array: count
• pointer to the string comparison function: cmp_func

You also need to implement the following four string comparison functions:

1. int lexicographic_sort(char *, char*) to sort the strings in lexicographically non-decreasing order.
2. int lexicographic_sort_reverse(char *, char*) to sort the strings in lexicographically non-increasing order.
3. int sort_by_number_of_distinct_characters(char *, char*) to sort the strings in non-decreasing order of the number of distinct characters present in them. If two strings have the same number of distinct characters present in them, then the lexicographically smaller string should appear first.
4. int sort_by_length(char*, char*) to sort the strings in non-decreasing order of their lengths. If two strings have the same length, then the lexicographically smaller string should appear first.

Input Format

• 1 ≤ No. of Strings ≤ 50
• 1 ≤ Total Length of all the Strings ≤ 2500
• You have to write your own sorting function and you cannot use the inbuilt qsort function
• The strings consists of lower-case English Alphabets only.

Output Format

The locked code-stub will check the logic of your code. The output consists of the strings sorted according to the four comparsion functions in the order mentioned in the problem statement.

Sample Input 0

4
wkue
qoi
sbv
fekls

Sample Output 0

fekls
qoi
sbv
wkue

wkue
sbv
qoi
fekls

qoi
sbv
wkue
fekls

qoi
sbv
wkue
fekls

Solution - Sorting Array of String in C - Hacker Rank Solution 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int lexicographic_sort(const char* a, const char* b)
{
    return strcmp(a, b);
}

int lexicographic_sort_reverse(const char* a, const char* b)
{
    return strcmp(b, a);
}
int characters_count(const char *s)
{
    int n = 0;
    int count[128] = {0};
    if (NULL == s)
    {
        return -1;
    }
    while(*s != '\0')
    {
        if (!count[*s])
        {
            count[*s]++;
            n++;
        }
        s++;
    }
    return n;
}

int sort_by_number_of_distinct_characters(const char* a, const char* b)
{
    int con = characters_count(a) - characters_count(b);
    return (con ? con : lexicographic_sort(a, b));
}

int sort_by_length(const char* a, const char* b) 
{
    int len = strlen(a) - strlen(b);
    return (len ? len : lexicographic_sort(a, b));
}

void string_sort(char** arr,const int len,int (*cmp_func)(const char* a, const char* b))
{
    int mid = len / 2;
    int con = 0;
    while(!con)
    {
        con = 1;
        for(int i = 0; i < len - 1; i++)
        {
            if(cmp_func(arr[i], arr[i + 1]) > 0) 
            {
                char *temp = arr[i];
                arr[i] = arr[i + 1];
                arr[i + 1] = temp;
                con = 0;
            }
        }
    }
}


int main() 
{
    int n;
    scanf("%d", &n);
  
    char** arr;
	arr = (char**)malloc(n * sizeof(char*));
  
    for(int i = 0; i < n; i++)
    {
        *(arr + i) = malloc(1024 * sizeof(char));
        scanf("%s", *(arr + i));
        *(arr + i) = realloc(*(arr + i), strlen(*(arr + i)) + 1);
    }
  
    string_sort(arr, n, lexicographic_sort);
    for(int i = 0; i < n; i++)
        printf("%s\n", arr[i]);
    printf("\n");

    string_sort(arr, n, lexicographic_sort_reverse);
    for(int i = 0; i < n; i++)
        printf("%s\n", arr[i]); 
    printf("\n");

    string_sort(arr, n, sort_by_length);
    for(int i = 0; i < n; i++)
        printf("%s\n", arr[i]);    
    printf("\n");

    string_sort(arr, n, sort_by_number_of_distinct_characters);
    for(int i = 0; i < n; i++)
        printf("%s\n", arr[i]); 
    printf("\n");
}

Disclaimer: The above Problem (Sorting Array of Strings in C) is generated by Hacker Rank but the Solution is provide by Sloth Coders.

Happy Coding!!

A Sloth Who loves to Code

Also Read:

• Calculate the Nth Term in C - Hacker Rank Solution 
• Dynamic Array in C - Hacker Rank Solution 
• Digit frequency in C - Hacker Rank Solution 
• Printing Tokens in C - Hacker Rank Solution 
• Array Reversal in C - Hacker Rank Solution