according to the idea of gtm-nayan #144, add println!("Success") for each exercise

src/compound-types/array.md

@@ -19,6 +19,8 @@ fn main() {
 
     // modify below to make it work
     assert!(arr.len() == 4);
+
+    println!("Success!")
 }
 ```
 
@@ -34,6 +36,8 @@ fn main() {
     // Arrays are stack allocated, `std::mem::size_of_val` return the bytes which array occupies
     // A char takes 4 byte in Rust: Unicode char
     assert!(std::mem::size_of_val(&arr) == __);
+
+    println!("Success!")
 }
 ```
 
@@ -47,6 +51,8 @@ fn main() {
 
     assert!(list[0] == 1);
     assert!(list.len() == 100);
+
+    println!("Success!")
 }
 ```
 
@@ -56,6 +62,8 @@ fn main() {
 fn main() {
     // fix the error
     let _arr = [1, 2, '3'];
+
+    println!("Success!")
 }
 ```
 
@@ -68,6 +76,8 @@ fn main() {
     let ele = arr[1]; // only modify this line to make the code work!
 
     assert!(ele == 'a');
+
+    println!("Success!")
 }
 ```
 
@@ -83,6 +93,8 @@ fn main() {
 
     // but indexing is not safe
     let _name1 = &names[2];
+
+    println!("Success!")
 }
 
 ```

src/compound-types/enum.md

@@ -28,6 +28,8 @@ fn main() {
     // a enum variant can be converted to a integer by `as`
     assert_eq!(Number::One, Number1::One);
     assert_eq!(Number1::One, Number2::One);
+
+    println!("Success!")
 } 
 ```
 
@@ -45,6 +47,8 @@ enum Message {
 fn main() {
     let msg1 = Message::Move{__}; // instantiating with x = 1, y = 2 
     let msg2 = Message::Write(__); // instantiating with "hello, world!"
+
+    println!("Success!")
 } 
 ```
 
@@ -67,6 +71,8 @@ fn main() {
     } else {
         panic!("NEVER LET THIS RUN！");
     }
+
+    println!("Success!")
 } 
 ```
 

src/compound-types/slice.md

@@ -10,6 +10,8 @@ fn main() {
     let s1: [i32] = arr[0..2];
 
     let s2: str = "hello, world" as str;
+
+    println!("Success!")
 }
 ```
 
@@ -26,6 +28,8 @@ fn main() {
     // modify '6' to make it work
     // TIPS: slice( reference ) IS NOT an array, if it is an array, then `assert!` will passed: each of the two UTF-8 chars '中' and '国'  occupies 3 bytes, 2 * 3 = 6
     assert!(std::mem::size_of_val(&slice) == 6);
+
+    println!("Success!")
 }
 ```
 
@@ -37,6 +41,8 @@ fn main() {
   // fill the blanks to make the code work
   let slice: __ = __;
   assert_eq!(slice, &[2, 3, 4]);
+
+  println!("Success!")
 }
 ```
 
@@ -52,6 +58,8 @@ fn main() {
     let slice2 = &s[__];
 
     assert_eq!(slice1, slice2);
+
+    println!("Success!")
 }
 ```
 
@@ -64,6 +72,8 @@ fn main() {
     let slice = &s[0..2];
 
     assert!(slice == "你");
+
+    println!("Success!")
 }
 ```
 

src/compound-types/string.md

@@ -10,6 +10,8 @@ The type of string literal `"hello, world"` is `&str`, e.g `let s: &str = "hello
 // fix error without adding new line
 fn main() {
    let s: str = "hello, world";
+
+   println!("Success!")
 }
 ```
 
@@ -42,6 +44,8 @@ fn main() {
    s.push('!');
 
    assert_eq!(s, "hello, world!");
+
+   println!("Success!")
 }
 ```
 
@@ -68,7 +72,9 @@ fn main() {
    // Allocate new memory and store the modified string there
    let s1 = s.__("dogs", "cats");
 
-   assert_eq!(s1, "I like cats")
+   assert_eq!(s1, "I like cats");
+
+   println!("Success!")
 }
 ```
 
@@ -113,6 +119,8 @@ fn greetings(s: String) {
 fn main() {
    let s =  "hello, world".to_string();
    let s1: &str = s;
+
+   println!("Success!")
 }
 ```
 
@@ -222,6 +230,8 @@ fn main() {
 
     let h1 = &s1[3..5];//modify this line to fix the error, tips: `中`  takes 3 bytes in UTF8 format
     assert_eq!(h1, "中");
+
+    println!("Success!")
 }
 ```
 

src/compound-types/struct.md

@@ -16,6 +16,8 @@ fn main() {
         name: String::from("sunface"),
         age,
     };
+
+    println!("Success!")
 } 
 ```
 
@@ -34,6 +36,8 @@ impl SomeTrait for Unit {  }
 fn main() {
     let u = Unit;
     do_something_with_unit(u);
+
+    println!("Success!")
 } 
 
 // fill the blank to make the code work
@@ -50,6 +54,8 @@ struct Point(i32, i32, i32);
 fn main() {
     let v = Point(__, __, __);
     check_color(v);
+
+    println!("Success!")
 }   
 
 fn check_color(p: Color) {
@@ -83,6 +89,8 @@ fn main() {
 
     // fill the lank
     __ = String::from("sunfei");
+
+    println!("Success!")
 }
 ```
 
@@ -94,7 +102,9 @@ struct Person {
     name: String,
     age: u8,
 }
-fn main() {} 
+fn main() {
+    println!("Success!")
+} 
 
 fn build_person(name: String, age: u8) -> Person {
     Person {
@@ -123,6 +133,8 @@ fn main() {
     };
 
     let u2 = set_email(u1);
+
+    println!("Success!")
 } 
 
 fn set_email(u: User) -> User {

src/compound-types/tuple.md

@@ -8,6 +8,8 @@ fn main() {
     let _t1: (u8, (i16, u32)) = (0, (-1, 1));
     // fill the blanks to make the code work
     let t: (u8, __, i64, __, __) = (1u8, 2u16, 3i64, "hello", String::from(", world"));
+
+    println!("Success!")
 }
 ```
 
@@ -18,6 +20,8 @@ fn main() {
 fn main() {
    let t = ("i", "am", "sunface");
    assert_eq!(t.1, "sunface");
+
+   println!("Success!")
 }
 ```
 
@@ -43,6 +47,8 @@ fn main() {
     assert_eq!(x, 1);
     assert_eq!(y, "hello");
     assert_eq!(z, 6.4);
+
+    println!("Success!")
 }
 ```
 
@@ -57,6 +63,8 @@ fn main() {
     assert_eq!(x, 3);
     assert_eq!(y, 1);
     assert_eq!(z, 2);
+
+    println!("Success!")
 }
 ```
 
@@ -69,6 +77,8 @@ fn main() {
 
    assert_eq!(x, 5);
    assert_eq!(y, 6);
+
+   println!("Success!")
 }
 
 fn sum_multiply(nums: (i32, i32)) -> (i32, i32) {