format code in md

solutions/collections/Hashmap.md

@@ -1,4 +1,5 @@
 1.
+
 ```rust
 // FILL in the blanks and FIX the erros
 use std::collections::HashMap;
@@ -29,6 +30,7 @@ fn main() {
 ```
 
 2.
+
 ```rust
 use std::collections::HashMap;
 fn main() {
@@ -73,9 +75,11 @@ fn main() {
 ```
 
 3.
+
 ```rust
 // FILL in the blanks
 use std::collections::HashMap;
+
 fn main() {
     // type inference lets us omit an explicit type signature (which
     // would be `HashMap<&str, u8>` in this example).
@@ -109,6 +113,7 @@ fn random_stat_buff() -> u8 {
 ```
 
 4.
+
 ```rust
 use std::collections::HashMap;
 
@@ -144,19 +149,21 @@ fn main() {
 ```
 
 5.
+
 ```rust
 use std::collections::HashMap;
-fn main() {
-  let v1 = 10;
-  let mut m1 = HashMap::new();
-  m1.insert(v1, v1);
-  println!("v1 is still usable after inserting to hashmap : {}", v1);
 
-  // &str implements Copy trait
-  let v2 = "hello";
-  let mut m2 = HashMap::new();
-  m2.insert(v2, v1);
-    
-  assert_eq!(v2, "hello");
+fn main() {
+    let v1 = 10;
+    let mut m1 = HashMap::new();
+    m1.insert(v1, v1);
+    println!("v1 is still usable after inserting to hashmap : {}", v1);
+
+    // &str implements Copy trait
+    let v2 = "hello";
+    let mut m2 = HashMap::new();
+    m2.insert(v2, v1);
+
+    assert_eq!(v2, "hello");
 }
 ```

solutions/collections/String.md

@@ -1,4 +1,5 @@
 1.
+
 ```rust
 fn main() {
     let mut s: String = String::from("hello, ");
@@ -36,6 +37,7 @@ fn borrow_string(s: &str) {
 ```
 
 2.
+
 ```rust
 // FILL in the blanks
 fn main() {  
@@ -82,6 +84,7 @@ fn main() {
 
 
 4.
+
 ```rust
 fn main() {
     let s = String::from("hello, 世界");
@@ -102,6 +105,7 @@ fn main() {
 ```
 
 5.
+
 ```rust
 // FILL in the blanks
 fn main() {
@@ -123,6 +127,7 @@ fn main() {
 ```
 
 6.
+
 ```rust
 fn main() {
     let mut s = String::with_capacity(25);
@@ -139,6 +144,7 @@ fn main() {
 ```
 
 7.
+
 ```rust
 use std::mem;
 

solutions/collections/Vector.md

@@ -1,4 +1,5 @@
-1. 
+1.
+
 ```rust
 fn main() {
     let arr: [u8; 3] = [1, 2, 3];
@@ -30,6 +31,7 @@ fn is_vec(v: &Vec<u8>) {}
 ```
 
 2.
+
 ```rust
 fn main() {
     let mut v1 = Vec::from([1, 2, 4]);
@@ -45,7 +47,8 @@ fn main() {
 }
 ```
 
-3. 
+3.
+
 ```rust
 fn main() {
     // array -> Vec
@@ -72,7 +75,8 @@ fn main() {
  }
  ```
 
-4. 
+4.
+
 ```rust,editable
 fn main() {
     let mut v = Vec::from([1, 2, 3]);
@@ -94,7 +98,8 @@ fn main() {
 }
 ```
 
-5. 
+5.
+
 ```rust
 // FIX the errors
 fn main() {
@@ -119,7 +124,8 @@ fn main() {
 }
 ```
 
-6. 
+6.
+
 ```rust
 // FIX the errors
 fn main() {
@@ -155,20 +161,22 @@ fn main() {
 }
 ```
 
-7. 
+7.
+
 ```rust
 #[derive(Debug, PartialEq)]
 enum IpAddr {
     V4(String),
     V6(String),
 }
+
 fn main() {
     // FILL in the blank
-    let v : Vec<IpAddr>= vec![
+    let v: Vec<IpAddr> = vec![
         IpAddr::V4("127.0.0.1".to_string()),
         IpAddr::V6("::1".to_string())
     ];
-    
+
     // Comparing two enums need to derive the PartialEq trait
     assert_eq!(v[0], IpAddr::V4("127.0.0.1".to_string()));
     assert_eq!(v[1], IpAddr::V6("::1".to_string()));
@@ -177,7 +185,8 @@ fn main() {
 }
 ```
 
-8. 
+8.
+
 ```rust
 trait IpAddr {
     fn display(&self);