[feat/fix/docs]: Improved on conversion code , length variable , asserts added

conversions/binary_to_decimal.c

@@ -1,24 +1,94 @@
 /**
- * Modified 07/12/2017, Kyler Smith
- *
- */
+* A C code to convert a binary number to a decimal one.
+* Modified 07/12/2017, Kyler Smith
+* Modified 2021 lazy-dude
+*/
 
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h> 
 #include <stdio.h>
+#include <stdlib.h>
 
-int main()
+/**
+* function prototypes
+*/
+bool is_binary(intmax_t num);
+int num_len(intmax_t num);
+intmax_t binary_decimal(intmax_t num);
+void test(void);
+
+int main(void)
+{
+    test();
+    printf("All tests passed.\n");
+    return 0;
+}
+
+/**
+* is_binary checks whether num is a binary one
+*/
+bool is_binary(intmax_t num)
 {
-    int remainder, number = 0, decimal_number = 0, temp = 1;
-    printf("\n Enter any binary number= ");
-    scanf("%d", &number);
+    int remainder = 0;
+
+    while (num > 0) {
+        remainder = num % 10;
+        if (remainder == 0 || remainder == 1) {
+            num /= 10;
+            continue;
+        } else
+            return false;
+    }
+    return true;
+}
+
+/**
+* num_len finds length of an intmax_t num
+*/
+int num_len(intmax_t num)
+{
+    int i;
+    for (i = 0; num > 0; i++) {
+        num /= 10;
+    }
+    return i;
+}
+
+/**
+* binary_decimal function does the actual job of conversion
+*/
+intmax_t binary_decimal(intmax_t number)
+{
+	intmax_t remainder, decimal_number = 0, temp = 1;
+
+    int length = num_len(INTMAX_MAX) - 1;
+
+    assert(number>=0);
+    assert(num_len(number) <= length);
+    assert(is_binary(number));
 
     // Iterate over the number until the end.
-    while (number > 0)
-    {
+    while (number > 0) {
         remainder = number % 10;
         number = number / 10;
         decimal_number += remainder * temp;
-        temp = temp * 2;  // used as power of 2
+        temp = temp * 2; // used as power of 2
     }
 
-    printf("%d\n", decimal_number);
+    return decimal_number;
 }
+
+/**
+* some tests using assert
+*/
+void test(void)
+{
+	assert(binary_decimal(0)==0);
+	assert(binary_decimal(1)==1);
+	assert(binary_decimal(1110001)==113);
+	assert(binary_decimal(11111111)==255);
+	assert(binary_decimal(10000000000)==1024);
+	assert(binary_decimal(1001110100000100)==40196);
+}
+

conversions/decimal_to_hexa.c

@@ -18,6 +18,7 @@ int main()
  * number****************/
 void decimal2Hexadecimal(long num)
 {
+	char hex_letters[]="abcdef";
     long decimalnum = num;
     long quotient, remainder;
     int i, j = 0;
@@ -29,17 +30,17 @@ void decimal2Hexadecimal(long num)
     {
         remainder = quotient % 16;
         if (remainder < 10)
-            hexadecimalnum[j++] = 48 + remainder;
+            hexadecimalnum[j++] = '0' + remainder;
 
         else
-            hexadecimalnum[j++] = 55 + remainder;
+            hexadecimalnum[j++] =  hex_letters[remainder-10];// 'A'
 
         quotient = quotient / 16;
     }
 
     // print the hexadecimal number
-
-    for (i = j; i >= 0; i--)
+	printf("0x");
+    for (i = j-1; i >= 0; i--)
     {
         printf("%c", hexadecimalnum[i]);
     }