Merge pull request kennyledet#480 from jb1717/master

patrickyevsukov · patrickyevsukov · commit 193947fb7bb0 · 2015-09-07T21:56:48.000-04:00
Harshad number C implementation
diff --git a/10_Harshad_Number/C/jb1717/10_Harshad_Number.c b/10_Harshad_Number/C/jb1717/10_Harshad_Number.c
@@ -0,0 +1,29 @@
+/*
+** A harshad number is an integer that is divisible by the sum of its digits
+** Here we only use the base 10
+** For more information : https://en.wikipedia.org/wiki/Harshad_number
+*/
+
+static int sumDigit(int n)
+{
+  int sum = 0;
+
+  while (n)
+    {
+      sum += n % 10;
+      n /= 10;
+    }
+  return (sum);
+}
+
+/*
+** Return if the number is Harshad or not
+*/
+int isHarshad(int n)
+{
+  int sum = sumDigit(n);
+
+  if (!sum)
+    return (0);
+  return (n % sum == 0);
+}
diff --git a/10_Harshad_Number/C/jb1717/10_Harshad_Number.h b/10_Harshad_Number/C/jb1717/10_Harshad_Number.h
@@ -0,0 +1,6 @@
+#ifndef HARSHAD_NUMBER
+# define HARSHAD_NUMBER
+
+int isHarshad(int n);
+
+#endif
diff --git a/10_Harshad_Number/C/jb1717/10_Harshad_Number_test.c b/10_Harshad_Number/C/jb1717/10_Harshad_Number_test.c
@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <assert.h>
+#include "10_Harshad_Number.h"
+
+/*
+** This test try all number between 1 and 200 and print only harshad numbers
+*/
+int main(void)
+{
+  int pretty = 0;
+  int idx = 0;
+  int sample[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+		  12, 18, 20, 21, 24, 27, 30, 36,
+		  40, 42, 45, 48, 50, 54, 60, 63,
+		  70, 72, 80, 81, 84, 90, 100, 102,
+		  108, 110, 111, 112, 114, 117, 120,
+		  126, 132, 133, 135, 140, 144, 150,
+		  152,153, 156, 162, 171, 180, 190,
+		  192, 195, 198, 200};
+
+  printf("Display all Harshad numbers between 1 and 200\n\n");
+
+  for (int i = 0; i < 201; ++i)
+    {
+      if (isHarshad(i))
+	{
+	  // if a number is consider Harshad but not in the sample
+	  assert(sample[idx++] == i);
+
+	  printf("%d", i);
+	  pretty++;
+	  if (pretty % 5 == 0)
+	    printf("\n");
+	  else
+	    printf("\t");
+	}
+    }
+  printf("\n\n=== END ===\n\n");
+  return (0);
+}
