C: nucleotide-count & rna-transcription

c/nucleotide-count/src/nucleotide_count.c

@@ -0,0 +1,68 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include "nucleotide_count.h"
+
+typedef unsigned char uchar;
+
+static int C[256] = {
+    ['A']=1, ['C']=2, ['G']=3, ['T']=4
+};
+
+/* not in C99: we implement asprintf */
+static char *asprintf(const char *fmt, ...)
+{
+    int n = 0;
+    char *p = NULL;
+    va_list ap;
+
+    va_start(ap, fmt);
+    n = vsnprintf(p, 0, fmt, ap);
+    va_end(ap);
+
+    if (n < 0 || !(p=malloc(n+1)))
+        return NULL;
+
+    va_start(ap, fmt);
+    n = vsnprintf(p, n+1, fmt, ap);
+    va_end(ap);
+    if (n < 0) {
+        free(p);
+        return NULL;
+    }
+
+    return p;
+}
+
+char *count(const char *dna)
+{
+    int res[4]={ 0 };
+
+    if (!dna)
+        return NULL;                              /* should it be "" ? */
+
+    for (const uchar *p=(uchar *)dna; *p; ++p) {
+        if (!C[*p])
+            return asprintf("");
+        res[C[*p]-1]++;
+    }
+    return asprintf("A:%d C:%d G:%d T:%d", res[0], res[1], res[2], res[3]);
+}
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#ifdef UNIT_TEST
+int main(int ac, char **av)
+{
+    int arg=1;
+    char *p;
+
+    //printf("%s: %s\n", asprintf("%d %d %d %d %s", (long)av-(long)av, ac, arg, 1000, "foobar"));
+    for (; arg<ac; ++arg) {
+        p=count(av[arg]);
+        printf("%s: [%s] len=%lu\n", av[arg], p, strlen(p));
+    }
+}
+#endif

c/nucleotide-count/src/nucleotide_count.h

@@ -0,0 +1,18 @@
+#ifndef _NUCLEOTIDE_COUNT_H
+#define _NUCLEOTIDE_COUNT_H
+
+char *count(const char *dna_strand);
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#if defined UNIT_TEST || defined DEBUG
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+#ifdef  TESTALL
+#undef  TEST_IGNORE
+#define TEST_IGNORE() {}
+#endif
+
+#endif