feat: add rust solution to lc problem: No.1316 (doocs#1163)

Author: xzhseh

Diff for: solution/1300-1399/1316.Distinct Echo Substrings/README.md

@@ -161,6 +161,53 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+use std::collections::HashSet;
+
+const BASE: u64 = 131;
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn distinct_echo_substrings(text: String) -> i32 {
+        let n = text.len();
+        let mut vis: HashSet<u64> = HashSet::new();
+        let mut base_vec: Vec<u64> = vec![1; n + 1];
+        let mut hash_vec: Vec<u64> = vec![0; n + 1];
+
+        // Initialize the base vector & hash vector
+        for i in 0..n {
+            let cur_char = (text.chars().nth(i).unwrap() as u8 - 'a' as u8 + 1) as u64;
+            // Update base vector
+            base_vec[i + 1] = base_vec[i] * BASE;
+            // Update hash vector
+            hash_vec[i + 1] = hash_vec[i] * BASE + cur_char;
+        }
+
+        // Traverse the text to find the result pair, using rolling hash
+        for i in 0..n - 1 {
+            for j in i + 1..n {
+                // Prevent overflow
+                let k = i + (j - i) / 2;
+                let left = Self::get_hash(i + 1, k + 1, &base_vec, &hash_vec);
+                let right = Self::get_hash(k + 2, j + 1, &base_vec, &hash_vec);
+                if left == right {
+                    vis.insert(left);
+                }
+            }
+        }
+
+        vis.len() as i32
+    }
+
+    #[allow(dead_code)]
+    fn get_hash(start: usize, end: usize, base_vec: &Vec<u64>, hash_vec: &Vec<u64>) -> u64 {
+        hash_vec[end] - hash_vec[start - 1] * base_vec[end - start + 1]
+    }
+}
+```
+
 ### **Go**
 
 ```go

Diff for: solution/1300-1399/1316.Distinct Echo Substrings/README_EN.md

@@ -137,6 +137,53 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+use std::collections::HashSet;
+
+const BASE: u64 = 131;
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn distinct_echo_substrings(text: String) -> i32 {
+        let n = text.len();
+        let mut vis: HashSet<u64> = HashSet::new();
+        let mut base_vec: Vec<u64> = vec![1; n + 1];
+        let mut hash_vec: Vec<u64> = vec![0; n + 1];
+
+        // Initialize the base vector & hash vector
+        for i in 0..n {
+            let cur_char = (text.chars().nth(i).unwrap() as u8 - 'a' as u8 + 1) as u64;
+            // Update base vector
+            base_vec[i + 1] = base_vec[i] * BASE;
+            // Update hash vector
+            hash_vec[i + 1] = hash_vec[i] * BASE + cur_char;
+        }
+
+        // Traverse the text to find the result pair, using rolling hash
+        for i in 0..n - 1 {
+            for j in i + 1..n {
+                // Prevent overflow
+                let k = i + (j - i) / 2;
+                let left = Self::get_hash(i + 1, k + 1, &base_vec, &hash_vec);
+                let right = Self::get_hash(k + 2, j + 1, &base_vec, &hash_vec);
+                if left == right {
+                    vis.insert(left);
+                }
+            }
+        }
+
+        vis.len() as i32
+    }
+
+    #[allow(dead_code)]
+    fn get_hash(start: usize, end: usize, base_vec: &Vec<u64>, hash_vec: &Vec<u64>) -> u64 {
+        hash_vec[end] - hash_vec[start - 1] * base_vec[end - start + 1]
+    }
+}
+```
+
 ### **Go**
 
 ```go

Diff for: solution/1300-1399/1316.Distinct Echo Substrings/Solution.rs

@@ -0,0 +1,42 @@
+use std::collections::HashSet;
+
+const BASE: u64 = 131;
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn distinct_echo_substrings(text: String) -> i32 {
+        let n = text.len();
+        let mut vis: HashSet<u64> = HashSet::new();
+        let mut base_vec: Vec<u64> = vec![1; n + 1];
+        let mut hash_vec: Vec<u64> = vec![0; n + 1];
+
+        // Initialize the base vector & hash vector
+        for i in 0..n {
+            let cur_char = (text.chars().nth(i).unwrap() as u8 - 'a' as u8 + 1) as u64;
+            // Update base vector
+            base_vec[i + 1] = base_vec[i] * BASE;
+            // Update hash vector
+            hash_vec[i + 1] = hash_vec[i] * BASE + cur_char;
+        }
+
+        // Traverse the text to find the result pair, using rolling hash
+        for i in 0..n - 1 {
+            for j in i + 1..n {
+                // Prevent overflow
+                let k = i + (j - i) / 2;
+                let left = Self::get_hash(i + 1, k + 1, &base_vec, &hash_vec);
+                let right = Self::get_hash(k + 2, j + 1, &base_vec, &hash_vec);
+                if left == right {
+                    vis.insert(left);
+                }
+            }
+        }
+
+        vis.len() as i32
+    }
+
+    #[allow(dead_code)]
+    fn get_hash(start: usize, end: usize, base_vec: &Vec<u64>, hash_vec: &Vec<u64>) -> u64 {
+        hash_vec[end] - hash_vec[start - 1] * base_vec[end - start + 1]
+    }
+}