Added octal to decimal

conversions/octal_to_decimal.c

@@ -0,0 +1,38 @@
+#include <math.h>
+#include <stdio.h>
+
+// Converts octal number to decimal
+int convertValue(int num, int i) {
+    return num * pow(8, i);
+}
+
+long long toDecimal(int octal_value) {
+
+    int decimal_value = 0, i = 0;
+
+    while (octal_value) {
+
+        // Extracts right-most digit and then multiplies by 8^i
+        decimal_value += convertValue(octal_value % 10, i++);
+
+        // Shift right in base 10
+        octal_value /= 10;
+    }
+
+    return decimal_value;
+}
+
+int main() {
+
+    printf("Enter octal value: ");
+
+    int octal_value;
+
+    scanf("%d", &octal_value);
+
+    long long result = toDecimal(octal_value);
+
+    printf("%d in decimal is %lld\n", octal_value, result);
+
+    return 0;
+}