format code in md

solutions/functional-programing/closure.md

@@ -1,4 +1,5 @@
 1、
+
 ```rust
 fn main() {
     let color = String::from("green");
@@ -13,6 +14,7 @@ fn main() {
 ```
 
 2、
+
 ```rust
 fn main() {
     let mut count = 0;
@@ -38,6 +40,7 @@ fn main() {
 ```
 
 3、
+
 ```rust
 fn main() {
      // A non-copy type.
@@ -83,6 +86,7 @@ fn take<T>(_v: &T) {
 ```
 
 4、
+
 ```rust
 fn main() {
     let example_closure = |x| x;
@@ -95,6 +99,7 @@ fn main() {
 ```
 
 5、
+
 ```rust
 fn fn_once<F>(func: F)
 where
@@ -126,6 +131,7 @@ fn main() {
 ```
 
 6、
+
 ```rust
 fn main() {
     let mut s = String::new();
@@ -143,6 +149,7 @@ fn exec<'a, F: FnMut(&'a str)>(mut f: F)  {
 ```
 
 7、
+
 ```rust
 // A function which takes a closure as an argument and calls it.
 // <F> denotes that F is a "Generic type parameter"
@@ -197,6 +204,7 @@ fn main() {
 ```
 
 8、
+
 ```rust
 fn main() {
     let mut s = String::new();
@@ -212,6 +220,7 @@ fn exec<'a, F: FnOnce(&'a str) -> String>(mut f: F) {
 ```
 
 9、
+
 ```rust
 // Define a function which takes a generic `F` argument
 // bounded by `Fn`, and calls it
@@ -234,6 +243,7 @@ fn main() {
 ```
 
 10、
+
 ```rust
 /* Fill in the blank and fix the errror */
 // You can aslo use `impl FnOnce(i32) -> i32`
@@ -268,6 +278,7 @@ fn main() {
 ```
 
 11、
+
 ```rust
 // Every closure has its own type. Even if one closure has the same representation as another, their types are different.
 fn factory(x:i32) -> Box<dyn Fn(i32) -> i32> {

solutions/functional-programing/iterator.md

@@ -1,4 +1,5 @@
 1、
+
 ```rust
 fn main() {
     let arr = [0; 10];
@@ -9,6 +10,7 @@ fn main() {
 ```
 
 2、
+
 ```rust
 fn main() {
     let mut v = Vec::new();
@@ -21,6 +23,7 @@ fn main() {
 ```
 
 3、
+
 ```rust
 fn main() {
     let v1 = vec![1, 2];
@@ -48,6 +51,7 @@ fn main() {
 ```
 
 4、
+
 ```rust
 fn main() {
     let arr = vec![0; 10];
@@ -60,6 +64,7 @@ fn main() {
 ```
 
 5、
+
 ```rust
 fn main() {
     let mut names = vec!["Bob", "Frank", "Ferris"];
@@ -76,6 +81,7 @@ fn main() {
 ```
 
 6、
+
 ```rust
 fn main() {
     let mut values = vec![1, 2, 3];
@@ -90,6 +96,7 @@ fn main() {
 ```
 
 7、
+
 ```rust
 struct Fibonacci {
     curr: u32,
@@ -136,6 +143,7 @@ fn main() {
 ```
 
 8、
+
 ```rust
 fn main() {
     let v1 = vec![1, 2, 3];
@@ -152,6 +160,7 @@ fn main() {
 ```
 
 9、
+
 ```rust
 use std::collections::HashMap;
 fn main() {
@@ -169,6 +178,7 @@ fn main() {
 ```
 
 10、
+
 ```rust
 fn main() {
     let v1: Vec<i32> = vec![1, 2, 3];
@@ -180,6 +190,7 @@ fn main() {
 ```
 
 11、
+
 ```rust
 use std::collections::HashMap;
 fn main() {
@@ -192,6 +203,7 @@ fn main() {
 ```
 
 12、
+
 ```rust
 #[derive(PartialEq, Debug)]
 struct Shoe {