conversion program added

SOLUTIONS/ OctalDecimalConversion.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <math.h>
+
+int convertDecimalToOctal(int decimalNumber);
+long long convertOctalToDecimal(int octalNumber);
+int main()
+{
+    int choice,decimalNumber,octalNumber;
+    printf("Select what you want to convert:\n");
+    printf("1. Decimal to Octal:\n");
+    printf("2. Octal to Decimal:\n");
+    scanf("%d",&choice);
+    switch(choice)
+    {
+        case 1:
+        printf("Enter a decimal number: ");
+        scanf("%d",&decimalNumber);
+        printf("%d in decimal = %d in octal", decimalNumber, convertDecimalToOctal(decimalNumber));
+        break;
+
+        case 2:
+        printf("Enter an octal number: ");
+        scanf("%d", &octalNumber);
+        printf("%d in octal = %lld in decimal", octalNumber, convertOctalToDecimal(octalNumber));
+        break;
+        default :
+        printf("Wrong choice!\n");
+
+
+
+    }
+    return 0;
+}
+
+int convertDecimalToOctal(int decimalNumber)
+{
+    int octalNumber = 0, i = 1;
+
+    while (decimalNumber != 0)
+    {
+        octalNumber += (decimalNumber % 8) * i;
+        decimalNumber /= 8;
+        i *= 10;
+    }
+
+    return octalNumber;
+}
+
+long long convertOctalToDecimal(int octalNumber)
+{
+    int decimalNumber = 0, i = 0;
+
+    while(octalNumber != 0)
+    {
+        decimalNumber += (octalNumber%10) * pow(8,i);
+        ++i;
+        octalNumber/=10;
+    }
+
+    i = 1;
+
+    return decimalNumber;
+}