add solutions for variables

src/basic-types/char-bool-unit.md

@@ -88,3 +88,5 @@ fn main() {
     assert!(size_of_val(&unit) == 4);
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/basic-types/functions.md

@@ -41,3 +41,5 @@ fn never_return() -> ! {
     
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/basic-types/numbers.md

@@ -163,3 +163,5 @@ fn main() {
     println!("0x80 >> 2 is 0x{:x}", 0x80u32 >> 2);
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/basic-types/statements-expressions.md

@@ -57,3 +57,5 @@ fn sum(x: i32, y: i32) -> i32 {
     x + y;
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/compound-types/array.md

@@ -87,3 +87,4 @@ fn main() {
 
 ```
 
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/compound-types/enum.md

@@ -70,7 +70,7 @@ fn main() {
 } 
 ```
 
-🌟🌟 使用枚举对类型进行同一化
+🌟🌟 
 
 ```rust,editable
 
@@ -199,3 +199,5 @@ fn main() {
     println!("{}", list.stringify());
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/compound-types/slice.md

@@ -86,3 +86,5 @@ fn first_word(s: &str) -> &str {
     &s[..1]
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/compound-types/string.md

@@ -251,5 +251,4 @@ fn main() {
 }
 ```
 
-
-
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/compound-types/struct.md

@@ -214,3 +214,5 @@ fn main() {
     println!("{}, {}, {:?}",f.name, f.data, f);
 } 
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/compound-types/tuple.md

@@ -75,3 +75,5 @@ fn sum_multiply(nums: (i32, i32)) -> (i32, i32) {
     (nums.0 + nums.1, nums.0 * nums.1)
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/flow-control.md

@@ -243,3 +243,5 @@ fn main() {
     assert!(count == __)
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/ownership/borrowing.md

@@ -164,3 +164,5 @@ fn main() {
     // you can't use r1 and r2 at the same time
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/ownership/ownership.md

@@ -161,3 +161,6 @@ fn main() {
    println!("{:?}, {:?}, {:?}", s1, s2, t);
 }
 ```
+
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/pattern-match/match-iflet.md

@@ -193,3 +193,6 @@ fn main() {
     }
  }
  ```
+
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/pattern-match/patterns.md

@@ -96,3 +96,5 @@ fn main() {
     }
 }
 ```
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

src/variables.md

@@ -144,3 +144,6 @@ fn main() {
     assert_eq!([x,y], __);
 } 
 ```
+
+
+> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it

zh-CN/src/basic-types/char-bool-unit.md

@@ -85,3 +85,5 @@ fn main() {
     assert!(size_of_val(&unit) == 4);
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/basic-types/functions.md

@@ -41,3 +41,5 @@ fn never_return() -> ! {
     
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/basic-types/numbers.md

@@ -163,3 +163,5 @@ fn main() {
     println!("0x80 >> 2 is 0x{:x}", 0x80u32 >> 2);
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/basic-types/statements-expressions.md

@@ -57,3 +57,5 @@ fn sum(x: i32, y: i32) -> i32 {
     x + y;
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/compound-types/array.md

@@ -83,3 +83,4 @@ fn main() {
 }
 ```
 
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/compound-types/enum.md

@@ -190,3 +190,5 @@ fn main() {
     println!("{}", list.stringify());
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/compound-types/slice.md

@@ -88,3 +88,5 @@ fn first_word(s: &str) -> &str {
     &s[..1]
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/compound-types/string.md

@@ -255,4 +255,4 @@ fn main() {
 ```
 
 
-
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/compound-types/struct.md

@@ -215,4 +215,6 @@ fn main() {
     println!("{}, {}, {:?}",f.name, f.data, f);
 } 
 ```
-```
+
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/compound-types/tuple.md

@@ -75,3 +75,6 @@ fn sum_multiply(nums: (i32, i32)) -> (i32, i32) {
     (nums.0 + nums.1, nums.0 * nums.1)
 }
 ```
+
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/flow-control.md

@@ -241,3 +241,5 @@ fn main() {
     assert!(count == __)
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/ownership/borrowing.md

@@ -164,3 +164,5 @@ fn main() {
     // 你不能同时使用 r1 和 r2
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/ownership/ownership.md

@@ -165,3 +165,5 @@ fn main() {
    println!("{:?}, {:?}, {:?}", s1, s2, t);
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/pattern-match/match-iflet.md

@@ -192,4 +192,6 @@ fn main() {
         _ => ()
     }
  }
- ```
+```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/pattern-match/patterns.md

@@ -96,3 +96,5 @@ fn main() {
     }
 }
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下) 

zh-CN/src/variables.md

@@ -142,3 +142,5 @@ fn main() {
     assert_eq!([x,y], __);
 } 
 ```
+
+> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下)