initial commit

c/resistor-color-trio/src/resistor_color_trio.c

@@ -0,0 +1,62 @@
+#include "resistor_color_trio.h"
+
+#if defined UNIT_TEST || defined DEBUG
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+
+static const unsigned p10[] = {
+    1e0, 1e1, 1e2, 1e3, 1e4,
+    1e5, 1e6, 1e7, 1e8, 1e9,
+};
+static const unsigned unit[] = {
+    p10[9], p10[6], p10[3], p10[0]
+};
+
+#define S(a) ((int)(sizeof(a)/sizeof(*a)))
+#define RB_OK(b) ((b)>=BLACK && (b)<=WHITE)
+
+static resistor_value_t ui2val(unsigned value)
+{
+    resistor_value_t res={0, OHMS};
+    int i;
+
+    for (i=0; i<S(unit); ++i) {
+        if (!(value%unit[i])) {
+            res.value=value/unit[i];
+            res.unit=i;
+            break;
+        }
+    }
+    return res;
+}
+
+resistor_value_t color_code(resistor_band_t *colors)
+{
+    resistor_band_t c1=*colors, c2=*(colors+1), c3=*(colors+2);
+    resistor_value_t res={RB_ERR, UN_ERR};
+
+    if (RB_OK(c1) && RB_OK(c2) && RB_OK(c3))
+        res=ui2val((c1*10+c2) * p10[c3]);
+    return res;
+}
+
+/* See GNUmakefile below for explanation
+ * https://exercism.io/my/solutions/103b2f7d92db42309c1988030f5202c7
+ */
+#ifdef UNIT_TEST
+int main(int ac, char **av)
+{
+    int arg=1;
+    resistor_band_t i[3];
+    resistor_value_t res;
+
+    for (; arg<ac-2; arg+=3) {
+        *i=atoi(av[arg]);
+        *(i+1)=atoi(av[arg+1]);
+        *(i+2)=atoi(av[arg+2]);
+        res=color_code(i);
+        printf("color(%d, %d, %d)=%d, %d\n", i[0], i[1], i[2], res.value, res.unit);
+    }
+}
+#endif

c/resistor-color-trio/src/resistor_color_trio.h

@@ -0,0 +1,45 @@
+#ifndef RESISTOR_COLOR_TRIO_H
+#define RESISTOR_COLOR_TRIO_H
+
+typedef enum {
+    BLACK=0,
+    BROWN,
+    RED,
+    ORANGE,
+    YELLOW,
+    GREEN,
+    BLUE,
+    VIOLET,
+    GREY,
+    WHITE,
+    RB_ERR=-1,
+} resistor_band_t;
+
+/* max=white-white-white =99 000 000 000=99 Giga
+ * warning: overflow before that (untested) !
+ */
+typedef enum {
+    GIGAOHMS=0,
+    MEGAOHMS,
+    KILOOHMS,
+    OHMS,
+    UN_ERR=-1
+} unit_t;
+
+typedef struct {
+    resistor_band_t value;
+    unit_t unit;
+} resistor_value_t;
+
+extern resistor_value_t color_code(resistor_band_t *);
+
+/* Note: For explanation on section below, see 'GNUfilename' included in
+ * link below :
+ * https://exercism.io/my/solutions/103b2f7d92db42309c1988030f5202c7
+ */
+#ifdef TESTALL
+#undef  TEST_IGNORE
+#define TEST_IGNORE() {}
+#endif
+
+#endif