Step 2: The C version

C has no built-in dictionary or string type, so you build the pieces: a fixed-size array of struct Entry (word and count), a loop that scans for an existing word (strcmp) or adds a new one, a loop that splits the text by hand with isalpha, and qsort with your own comparison function. It is more code, but nothing is hidden: you see exactly how counting works.

ExampleC

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MAX_WORDS 100
#define MAX_LEN 32

struct Entry {
  char word[MAX_LEN];
  int count;
};

static struct Entry entries[MAX_WORDS];
static int used = 0;

void add_word(const char *word) {
  for (int i = 0; i < used; i++) {
    if (strcmp(entries[i].word, word) == 0) {
      entries[i].count++;
      return;
    }
  }
  if (used < MAX_WORDS) {
    strncpy(entries[used].word, word, MAX_LEN - 1);
    entries[used].count = 1;
    used++;
  }
}

int by_count_then_word(const void *a, const void *b) {
  const struct Entry *x = a, *y = b;
  if (x->count != y->count) return y->count - x->count;
  return strcmp(x->word, y->word);
}

int main(void) {
  char text[] = "The quick brown fox jumps over the lazy dog. The end!";

  char word[MAX_LEN];
  int len = 0;
  for (char *p = text; ; p++) {
    if (isalpha((unsigned char)*p) && len < MAX_LEN - 1) {
      word[len++] = tolower((unsigned char)*p);
    } else {
      if (len > 0) {
        word[len] = '\0';
        add_word(word);
        len = 0;
      }
      if (*p == '\0') break;
    }
  }

  qsort(entries, used, sizeof(struct Entry), by_count_then_word);
  for (int i = 0; i < used; i++) {
    printf("%-6s %d\n", entries[i].word, entries[i].count);
  }
  return 0;
}

Output

the    3
brown  1
dog    1
end    1
fox    1
jumps  1
lazy   1
over   1
quick  1

What C asks of you: you choose the limits (MAX_WORDS, MAX_LEN) and must make sure you never write past them, because C will not stop you. In exchange you get a tiny, very fast program that uses almost no memory.

Quick check

What does C use instead of a built-in dictionary here?

A fixed array of structs searched by handA hash map from the languageA database

Finish the quick check (and any code exercise) to complete this lesson, or mark it done yourself.

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