[Sync Iteration] c/pig-latin/1

solutions/c/pig-latin/1/pig_latin.c

@@ -0,0 +1,79 @@
+#include "pig_latin.h"
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+static size_t capacity;
+static inline bool expand(char **p);
+static inline bool is_vowel(unsigned char c);
+static size_t consonant_cluster(const char *s);
+
+char *translate(const char *phrase){
+    if (!phrase) return NULL;
+
+    size_t len = strlen(phrase);
+    capacity = len << 1;
+    char *res = calloc(capacity, 1);
+    if (!res) return NULL;
+
+    size_t out = 0;
+
+    for (size_t i = 0; i < len; ){
+        size_t start = i;
+        while (i < len && phrase[i] != ' ') i++;
+        size_t wlen = i - start;
+
+        const char *w = phrase + start;
+        size_t cut = 0;
+
+        char f = tolower(w[0]);
+        char s = wlen > 1 ? tolower(w[1]) : 0;
+
+        if (!(is_vowel(f) || (f=='x'&&s=='r') || (f=='y'&&s=='t')))
+            cut = consonant_cluster(w);
+
+        if (out + wlen + 2 + 1 >= capacity)
+            if (!expand(&res)) { free(res); return NULL; }
+
+        memcpy(res + out, w + cut, wlen - cut);
+        out += wlen - cut;
+        memcpy(res + out, w, cut);
+        out += cut;
+        res[out++] = 'a';
+        res[out++] = 'y';
+
+        if (i < len) res[out++] = ' ';
+        i++;
+    }
+
+    res[out] = 0;
+    return res;
+}
+
+static inline bool expand(char **p){
+    capacity <<= 1;
+    char *t = realloc(*p, capacity);
+    if (!t) return false;
+    *p = t;
+    return true;
+}
+
+static inline bool is_vowel(unsigned char c){
+    c = tolower(c);
+    return c=='a'||c=='e'||c=='i'||c=='o'||c=='u';
+}
+
+static size_t consonant_cluster(const char *s){
+    size_t i = 0;
+    while (s[i]){
+        if (is_vowel(s[i])) break;
+        if (i > 0 && tolower(s[i]) == 'y') break;
+        if (tolower(s[i]) == 'q' && tolower(s[i+1]) == 'u'){
+            i += 2;
+            continue;
+        }
+        i++;
+    }
+    return i;
+}

solutions/c/pig-latin/1/pig_latin.h

@@ -0,0 +1,6 @@
+#ifndef PIG_LATIN_H
+#define PIG_LATIN_H
+
+char *translate(const char *phrase);
+
+#endif