Completed all functions exercises

exercises/functions/functions1.rs

@@ -4,8 +4,8 @@
 
 
 fn main() {
-    call_me();
+    call();
 }
-fn call_me () {
+fn call () {
 
 }

exercises/functions/functions2.rs

@@ -7,7 +7,7 @@ fn main() {
     call_me(3);
 }
 
-fn call_me(num: u8) {
+fn call_me(num:u8) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/functions/functions3.rs

@@ -4,7 +4,7 @@
 
 
 fn main() {
-    call_me(8);
+    call_me(9);
 }
 
 fn call_me(num: u32) {

exercises/functions/functions4.rs

@@ -14,7 +14,7 @@ fn main() {
     println!("Your sale price is {}", sale_price(original_price));
 }
 
-fn sale_price(price: i32) -> i32 {
+fn sale_price(price: i8) -> i8 {
     if is_even(price) {
         price - 10
     } else {
@@ -22,6 +22,6 @@ fn sale_price(price: i32) -> i32 {
     }
 }
 
-fn is_even(num: i32) -> bool {
+fn is_even(num: i8) -> bool {
     num % 2 == 0
 }