Question

I need writing a code that does the following:

//This program will prompt the user to enter a sentence, then get an entire line all at once
//print out the 1st word of the sentence by calling the first () finction
//print out the last word of the sentence by calling the last () function
//Free the dynamically allocated memory created b first ()

In C please

Answer 1

#include<stdio.h>
#include<string.h>
//definition of first function
void first(char str[])
{
    char *arr1;
    int i = 0,j=1;
    //store the first word in arr1[]
    while(str[i] != ' ')
    {
    //dynamically allocating the memory using realloc
       arr1 = (char*)realloc(arr1, j * sizeof(char));
       arr1[i] = str[i];
       i++;
       j++;
    }
    arr1[i] = '\0';
    //Displays the first word
    printf("First word: %s\n",arr1);
    //free the dynamically allocated memory
    free(arr1);
}
//definition of last function
void last(char str[])
{
    char arr[20];
    int j=0,len= 0;
    //calculating the length of the string
    len = strlen(str);
    len--;
   
    //logic to find the index of the last word
    while(str[len] != ' ')
    len--;
    //copy the last word into the another array
    while(str[len] != '\0')
    {
       arr[j] = str[len];
       len++;
       j++;
    }
    arr[j] = '\0';
    //Displays the last word
    printf("Last word: %s",arr);

}
//main function starts here
void main()
{
    char *str, c;
    int i = 0, j = 1;
    str = (char*)malloc(sizeof(char));
    printf("Enter String : ");
    while (c != '\n')
    {
        //read the input from user
        c = getc(stdin);
        //realloc is used to reallocate the memory dynamically
        str = (char*)realloc(str, j * sizeof(char));
        //store the each character in the array
        str[i] = c;
        i++;
        j++;
    }
    str[i] = '\0';
    // at the end append null character to mark end of string
    printf("\nEntered string is : %s\n", str);
   
    //calling the function first()
    first(str);
    //calling the function last()
    last(str);
   
    //free the dynamically allocated the memory
    free(str);
}