initial commit

c/square-root/src/square_root.c

@@ -0,0 +1,44 @@
+#include "square_root.h"
+
+/* See GNUmakefile in following link for explanation
+ * https://exercism.io/my/solutions/103b2f7d92db42309c1988030f5202c7
+ */
+#if defined UNIT_TEST || defined DEBUG
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+
+/* Newton's method:
+ * https://en.wikipedia.org/wiki/Newton%27s_method#Square_root
+ * return the largest integer equal or less than i square root.
+ */
+unsigned square_root(unsigned i)
+{
+    unsigned sq, sq2;
+
+    if (i<=1)                                     /* 0 and 1 */
+        return i;
+
+    sq = i/2;                                     /* we take i/2 as initial seed */
+    sq2 = ((i/sq) + sq) / 2;                      /* first iteration */
+
+    while (sq2 != sq) {
+        sq = sq2;
+        sq2 = ((i/sq) + sq) /2;                   /* next iteration */
+    }
+
+    return sq;
+}
+
+#ifdef UNIT_TEST
+int main(int ac, char **av)
+{
+    int arg=1;
+    unsigned i;
+
+    for (; arg<ac; ++arg) {
+        i=atol(av[arg]);
+        printf("sqrt(%u)=%u\n", i, square_root(i));
+    }
+}
+#endif

c/square-root/src/square_root.h

@@ -0,0 +1,16 @@
+#ifndef SQUARE_ROOT_H
+#define SQUARE_ROOT_H
+
+#include <stdint.h>
+
+extern unsigned square_root(unsigned);
+
+/* See GNUmakefile in following link for explanation
+ * https://exercism.io/my/solutions/103b2f7d92db42309c1988030f5202c7
+ */
+#ifdef  TESTALL
+#undef  TEST_IGNORE
+#define TEST_IGNORE() {}
+#endif
+
+#endif