Merge pull request #2024 from fwqaaq/patch-34

Update 0070.爬楼梯.md about rust

problems/0070.爬楼梯.md

@@ -454,18 +454,32 @@ public class Solution {
 ```rust
 impl Solution {
     pub fn climb_stairs(n: i32) -> i32 {
-        if n <= 2 {
+        if n <= 1 {
             return n;
         }
-        let mut a = 1;
-        let mut b = 2;
-        let mut f = 0;
-        for i in 2..n {
+        let (mut a, mut b, mut f) = (1, 1, 0);
+        for _ in 2..=n {
             f = a + b;
             a = b;
             b = f;
         }
-        return f;
+        f
+}
+```
+
+dp 数组
+
+```rust
+impl Solution {
+    pub fn climb_stairs(n: i32) -> i32 {
+        let n = n as usize;
+        let mut dp = vec![0; n + 1];
+        dp[0] = 1;
+        dp[1] = 1;
+        for i in 2..=n {
+            dp[i] = dp[i - 1] + dp[i - 2];
+        }
+        dp[n]
     }
 }
 ```