fix: show existing solutions to lcof problem: No.64

Author: YangFong

lcof/面试题64. 求1+2+…+n/README.md

@@ -52,6 +52,18 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+    public int sumNums(int n) {
+        int s = n;
+        boolean t = n > 0 && (s += sumNums(n - 1)) > 0;
+        return s;
+    }
+}
+```
+
 ### **JavaScript**
 
 ```js
@@ -79,6 +91,25 @@ func sumNums(n int) int {
 }
 ```
 
+### **TypeScript**
+
+```ts
+var sumNums = function (n: number): number {
+    return n && n + sumNums(n - 1);
+};
+```
+
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn sum_nums(mut n: i32) -> i32 {
+        n != 0 && (n += Solution::sum_nums(n - 1), true).1;
+        n
+    }
+}
+```
+
 ### **...**
 
 ```

lcof/面试题64. 求1+2+…+n/Solution.cpp

@@ -1,9 +1,7 @@
-class Solution
-{
+class Solution{
 public:
-  int sumNums(int n)
-  {
-    n && (n += sumNums(n - 1));
-    return n;
-  }
+    int sumNums(int n) {
+        n && (n += sumNums(n - 1));
+        return n;
+    }
 };

lcof/面试题64. 求1+2+…+n/Solution.rs

@@ -1,6 +1,6 @@
 impl Solution {
-  pub fn sum_nums(mut n: i32) -> i32 {
-      n!=0&&(n+=Solution::sum_nums(n-1),true).1;
-      n
-  }
-}
+    pub fn sum_nums(mut n: i32) -> i32 {
+        n != 0 && (n += Solution::sum_nums(n - 1), true).1;
+        n
+    }
+}