[Sync Iteration] c/anagram/1

solutions/c/anagram/1/anagram.c

@@ -0,0 +1,64 @@
+#include "anagram.h"
+#include <stddef.h>
+#include <string.h>
+#include <stdbool.h>
+#include <ctype.h>
+
+static bool is_anagram(const char *subject, const char *candidate) {
+   size_t len = strlen(subject);
+   // Count letter frequencies in subject
+   int subject_count[26] = {0};
+   for (size_t i = 0; i < len; i++) {
+      char c = tolower(subject[i]);
+      if (c >= 'a' && c <= 'z') {
+         subject_count[c - 'a']++;
+      }
+   }
+
+   // Subtract letter frequencies from candidate
+   for (size_t i = 0; i < len; i++) {
+      char c = tolower(candidate[i]);
+      if (c >= 'a' && c <= 'z') {
+         subject_count[c - 'a']--;
+      }
+      if (subject_count[c - 'a'] < 0) {
+         return false;
+      }
+   }
+
+   return true;
+}
+
+/**
+ * @description - determines if any of the words in candidate are anagrams
+ *                for subject. Contents of candidate structures may be modified.
+ */
+void find_anagrams(const char *subject, struct candidates *candidates) {
+   size_t len = strlen(subject);
+   for (size_t i = 0; i < candidates->count; i++) {
+      if (candidates->candidate[i].is_anagram == UNCHECKED) {
+         // check word length to avoid index out of bounds
+         if (len != strlen(candidates->candidate[i].word)) {
+            candidates->candidate[i].is_anagram = NOT_ANAGRAM;
+            continue;
+         }
+         // identical words are not anagrams
+         size_t j = 0;
+         for (; j < len; j++) {
+            if (tolower(subject[j]) != tolower(candidates->candidate[i].word[j])) {
+               break;
+            }
+         }
+         if (j == len) {
+            candidates->candidate[i].is_anagram = NOT_ANAGRAM;
+         } else {
+            // check if the words are anagrams
+            if (is_anagram(subject, candidates->candidate[i].word)) {
+               candidates->candidate[i].is_anagram = IS_ANAGRAM;
+            } else {
+               candidates->candidate[i].is_anagram = NOT_ANAGRAM;
+            }
+         }
+      }
+   }
+}

solutions/c/anagram/1/anagram.h

@@ -0,0 +1,26 @@
+#ifndef ANAGRAM_H
+#define ANAGRAM_H
+
+#include <stddef.h>
+
+#define MAX_STR_LEN 20
+
+enum anagram_status { UNCHECKED = -1, NOT_ANAGRAM, IS_ANAGRAM };
+
+struct candidate {
+   enum anagram_status is_anagram;
+   const char *word;
+};
+
+struct candidates {
+   struct candidate *candidate;
+   size_t count;
+};
+
+/**
+ * @description - determines if any of the words in candidate are anagrams
+ *                for subject. Contents of candidate structures may be modified.
+ */
+void find_anagrams(const char *subject, struct candidates *candidates);
+
+#endif