[Sync Iteration] c/protein-translation/1

Author: exercism-solutions-syncer[bot]

solutions/c/protein-translation/1/protein_translation.c

@@ -0,0 +1,81 @@
+#include "protein_translation.h"
+#include <string.h>
+
+#define CODON_SIZE 3
+#define CODON_INVALID -1
+#define CODON_STOP -2
+
+int char_to_index(char c) {
+   switch (c) {
+      case 'A': return 0;
+      case 'C': return 1;
+      case 'G': return 2;
+      case 'U': return 3;
+      default: return -1;
+   }
+}
+
+// perfect hash
+int hash(char a, char b) {
+   int index_a = char_to_index(a);
+   int index_b = char_to_index(b);
+   if (index_a == -1 || index_b == -1) 
+      return -1;
+
+   return (index_a<<2) + index_b;
+
+}
+
+int lookup(const char *word) {
+   if (word[0] == 'A' && word[1] == 'U' && word[2] == 'G')
+      return Methionine;
+
+   if (word[0] == 'U')
+      switch (hash(word[1], word[2])) {
+         /* UAA */ case  0: return CODON_STOP;
+         /* UAC */ case  1: return Tyrosine;
+         /* UAG */ case  2: return CODON_STOP;
+         /* UAU */ case  3: return Tyrosine;
+
+         /* UCA */ case  4: return Serine;
+         /* UCC */ case  5: return Serine;
+         /* UCG */ case  6: return Serine;
+         /* UCU */ case  7: return Serine;
+
+         /* UGA */ case  8: return CODON_STOP;
+         /* UGC */ case  9: return Cysteine;
+         /* UGG */ case 10: return Tryptophan;
+         /* UGU */ case 11: return Cysteine;
+
+         /* UUA */ case 12: return Leucine;
+         /* UUC */ case 13: return Phenylalanine;
+         /* UUG */ case 14: return Leucine;
+         /* UUU */ case 15: return Phenylalanine;
+                   default: return CODON_INVALID;
+      }
+   return CODON_INVALID;
+}
+
+
+protein_t protein(const char *rna) {
+   protein_t p = { .valid = true, .count = 0 };
+
+   size_t len = strlen(rna);
+
+   int amino;
+   for (size_t i = 0; i < len; i += CODON_SIZE) {
+      amino = lookup(rna+i);
+
+      if (amino == CODON_INVALID) {
+         p.valid = false;
+         break;
+      }
+
+      if (amino == CODON_STOP) 
+         break;
+
+      p.amino_acids[p.count++] = amino;
+   }
+
+   return p;
+}

solutions/c/protein-translation/1/protein_translation.h

@@ -0,0 +1,27 @@
+#ifndef PROTEIN_TRANSLATION_H
+#define PROTEIN_TRANSLATION_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#define MAX_AMINO_ACIDS 10
+
+typedef enum {
+   Methionine,
+   Phenylalanine,
+   Leucine,
+   Serine,
+   Tyrosine,
+   Cysteine,
+   Tryptophan,
+} amino_acid_t;
+
+typedef struct {
+   bool valid;
+   size_t count;
+   amino_acid_t amino_acids[MAX_AMINO_ACIDS];
+} protein_t;
+
+protein_t protein(const char *const rna);
+
+#endif