fix: show lc problem No.1768 rust solution

No.0704.Binary Search

Author: YangFong

solution/0700-0799/0704.Binary Search/README_EN.md

@@ -132,6 +132,55 @@ var search = function (nums, target) {
 };
 ```
 
+### **Rust**
+
+Cycle:
+
+```rust
+use std::cmp::Ordering;
+
+impl Solution {
+    pub fn search(nums: Vec<i32>, target: i32) -> i32 {
+        let mut l = 0;
+        let mut r = nums.len();
+        while l < r {
+            let mid = l + r >> 1;
+            match nums[mid].cmp(&target) {
+                Ordering::Less => l = mid + 1,
+                Ordering::Greater => r = mid,
+                Ordering::Equal => return mid as i32,
+            }
+        }
+        -1
+    }
+}
+```
+
+Recursion:
+
+```rust
+use std::cmp::Ordering;
+
+impl Solution {
+    fn binary_search(nums: Vec<i32>, target: i32, l: usize, r: usize) -> i32 {
+        if l == r {
+            return if nums[l] == target { l as i32 } else { -1 };
+        }
+        let mid = l + r >> 1;
+        match nums[mid].cmp(&target) {
+            Ordering::Less => Self::binary_search(nums, target, mid + 1, r),
+            Ordering::Greater => Self::binary_search(nums, target, l, mid),
+            Ordering::Equal => mid as i32,
+        }
+    }
+
+    pub fn search(nums: Vec<i32>, target: i32) -> i32 {
+        let r = nums.len() - 1;
+        Self::binary_search(nums, target, 0, r)
+    }
+}
+```
+
 ### **...**
 
 ```