doc: add rust solution to README_EN.md

No.0473.Matchsticks to Square

Author: maolonglong

solution/0400-0499/0473.Matchsticks to Square/README_EN.md

@@ -167,6 +167,42 @@ func makesquare(matchsticks []int) bool {
 }
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn makesquare(matchsticks: Vec<i32>) -> bool {
+        let mut matchsticks = matchsticks;
+
+        fn dfs(matchsticks: &Vec<i32>, edges: &mut [i32; 4], u: usize, x: i32) -> bool {
+            if u == matchsticks.len() {
+                return true;
+            }
+            for i in 0..4 {
+                if i > 0 && edges[i - 1] == edges[i] {
+                    continue;
+                }
+                edges[i] += matchsticks[u];
+                if edges[i] <= x && dfs(matchsticks, edges, u + 1, x) {
+                    return true;
+                }
+                edges[i] -= matchsticks[u];
+            }
+            false
+        }
+
+        let sum: i32 = matchsticks.iter().sum();
+        if sum % 4 != 0 {
+            return false;
+        }
+        matchsticks.sort_by(|x, y| y.cmp(x));
+        let mut edges = [0; 4];
+
+        dfs(&matchsticks, &mut edges, 0, sum / 4)
+    }
+}
+```
+
 ### **...**
 
 ```