initial commit

c/word-count/src/word_count.c

@@ -0,0 +1,162 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "word_count.h"
+#include "hash.h"
+
+/* See GNUmakefile in following link for explanation
+ * https://exercism.io/my/solutions/103b2f7d92db42309c1988030f5202c7
+ */
+#if defined UNIT_TEST || defined DEBUG
+#include <stdlib.h>
+#endif
+
+/* Some cases are not well explained. So I will consider words mixing
+ * alphabetic characters and digits as invalid, as well as multiple "'"
+ * inside an alphabetic word:
+ * The following will return INVALID_WORD:
+ *   P2P
+ *   0xFF
+ *   A'2
+ * The following will return 2 numbers/words:
+ *   1'2
+ *   A''B
+ */
+
+/* get next word in string
+ */
+static word_t next_word(const char **p)
+{
+    word_t res={NULL, 0};
+    const char *q, *p1=*p;
+    static char tmp[1024];
+    int pos=0;
+
+#   ifdef DEBUG
+    printf("next_word(%s)\n", *p);
+#   endif
+    for (; *p1 && !isalpha(*p1) && !isdigit(*p1); ++p1)
+        ;
+
+    if (*p1) {
+        q=p1;
+        /* alphabetic word */
+        if (isalpha(*p1)) {
+            for (; *q &&(isalpha(*q) || *q=='\''); q++) {
+                if (*q=='\'' && *(q-1)=='\'') {   /* two consecutive apostrophes */
+                    res.len=INVALID_WORD;
+                    goto end;
+                }
+                tmp[pos++]=tolower(*q);
+            }
+            if (*(q-1) == '\'')
+                q--;
+            else if (isdigit(*q)) {               /* digit in word */
+                res.len=INVALID_WORD;
+                goto end;
+            }
+        } else {
+            for (; *q &&(isdigit(*q)); q++)
+                tmp[pos++]=tolower(*q);
+            if (isalpha(*q)) {                    /* alphabetic char in number */
+                res.len=INVALID_WORD;
+                goto end;
+            }
+
+        }
+        res.word=tmp;
+        res.len=q-p1;
+        *p=q;
+    }
+end:
+#   ifdef DEBUG
+    printf("next_word: [%s], %d\n", res.word? res.word: "NULL", res.len);
+#   endif
+    return res;
+}
+
+static int insert_word(word_count_word_t *words, word_t w, int pos)
+{
+#ifdef DEBUG
+    printf("insert words(len=%d word=[%.*s])\n", w.len, w.len, w.word);
+#endif
+
+    memcpy(words[pos].text, w.word, w.len);
+    words[pos].text[w.len]=0;
+    words[pos].count=0;
+    return 1;
+}
+
+int count_words(const char *sentence, word_count_word_t *words)
+{
+    word_t w;
+    int current=0, new, index;
+    hash_t *hash;
+    h_entry_t *e;
+#   ifdef DEBUG
+    const char *s=sentence;
+#   endif
+
+    hash=h_create(16);
+#   ifdef DEBUG
+    printf("count_words([%s], %p)\n", sentence, (void *)words);
+#   endif
+    for (; *sentence;) {
+        w=next_word(&sentence);
+        if (!w.word)
+            break;
+        if (w.len > MAX_WORD_LENGTH)
+            return EXCESSIVE_LENGTH_WORD;
+        if (!(e=h_entry_find(hash, (const unsigned char *)w.word, w.len))) {
+            if (current==MAX_WORDS)
+                return EXCESSIVE_NUMBER_OF_WORDS;
+            insert_word(words, w, current);
+            e=h_entry_add(hash, (void *)&words[current], w.len, &new);
+            current++;
+        }
+        index=(word_count_word_t *)e->data-&words[0];
+        words[index].count++;
+        //sentence=w.word+w.len;
+        //sentence+=w.len;
+#       ifdef DEBUG
+        printf("count_words: index=%d\n", index);
+        printf("offset=%d\n", (int)(sentence-s));
+#       endif
+    }
+    h_destroy(hash);
+    return current;
+}
+
+#ifdef UNIT_TEST
+static word_count_word_t wtable[MAX_WORDS];
+
+static void reset_wtable()
+{
+    memset(wtable, 0, sizeof(wtable));
+}
+static void print_wtable(int n)
+{
+    for (int i=0; i<n; ++i) {
+        printf ("%2d: %2d x \"%s\"\n", i, wtable[i].count, wtable[i].text);
+                //djb2_hash(wtable[i].text));
+    }
+
+}
+
+int main(int ac, char **av)
+{
+    int arg=1;
+    int res;
+    //hash=h_create(16);
+    for (; arg<ac; ++arg) {
+        reset_wtable();
+        res=count_words(av[arg], wtable);
+        printf ("res=%d\n", res);
+        print_wtable(res);
+    }
+    //printf("h_destroy 1\n");
+    //h_destroy(hash);
+    //printf("h_destroy 1\n");
+}
+#endif