frequency.c

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

struct words

{

    char *word;        //struct words is a binary tree that stores a node and a pointer to the left and right siblings

    int count;

    struct words *left;

    struct words *right;

};

struct words *bintree(struct words **head,char *word);//bintree is a function of type struct words and the 1st arg is a pointer to the bin tree that stores the words

void print_tree(struct words *head);//print_tree is a function that prints a binary tree

char *readfile(char *filename);//readfile is a function that reads a text file and stores it in a string

int total;//an interger to store the total number of words in the file

int

main (int argc, char *argv[])

{

    char *word=NULL,*str=NULL;

    total = 0;

    struct words *head=NULL;

   

    if((str = readfile(argv[1])) != NULL)//

    {

       

        const char* delim = " ,\n\r\t.;:_-()~`|!?><%^&*$#@{}[]0123456789\'\"/";//delim is list of all chars that seperates two words form each other

        word = strtok(str,delim);//strtok is takes a string and seperates it into words using the delimities

        head = bintree(&head,word);

        while((word = strtok(NULL,delim)) != NULL){

            head = bintree(&head

            ,word);

        }

        printf("Total = %d\n",total);

        printf("|%-20s | %-5s |\n%25s\n","WORDS","freq","|============================");

        print_tree(head);

    }

    return 0;

}

void print_tree(struct words *head){

    if(head == NULL)

        return ;

    print_tree(head->right);//note that print_tree uses the post order traversal to print the tree

    printf("|%-20s | %-5d |\n",head->word,head->count);

    print_tree(head->left);

    return ;   

}

char *readfile(char *filename){

    FILE *fp = fopen(filename,"r");

    char *str=NULL;

    if(fp !=NULL){

        fseek(fp,0,SEEK_END);//moves the pointer 2 the end of the file

        long int size = ftell(fp);//ftel determine the size of the file

        rewind(fp);//rewind brings the pointer back to te beginning

        str = malloc(size + 1);

        fread(str,size,1,fp);//fread read the the entire file and stores it in a file.the 1 signifies it is reading the entire file as one block

        fclose(fp);

    }

    return str;

}

struct words *bintree(struct words **head,char *word){

    if(*head == NULL){

        *head = malloc(sizeof(struct words *));//allocate space for the words

        (*head)->word = malloc(sizeof(char) * strlen(word) + 1);

        strcpy((*head)->word,word);

        (*head)->count = 1;

        (*head)->left = (*head)->right = NULL;

        total++;

    }

    else if(strcasecmp((*head)->word,word) < 0){//strcasecmp compares without considering the cases

        bintree(&(*head)->left,word);

    }

    else if(strcasecmp((*head)->word,word) > 0){

        bintree(&(*head)->right,word);

    }

    else{

        (*head)->count++;

        total++;

    }

   

    return *head;

} 

/*To compile the file just do gcc -o frequency frequency.c

To run the file, just do ./frequency  the-name-of-the-file-you-want-to-count-the-words*/