From 960717ebc75ad5589d4142368a7581a7b21e0758 Mon Sep 17 00:00:00 2001
From: xiaolatiao <1628652790@qq.com>
Date: Sat, 29 Jul 2023 15:11:36 +0800
Subject: [PATCH] feat: add rust solution to lc problem: No.2475

Signed-off-by: xiaolatiao <1628652790@qq.com>
---
 .../README.md                                 | 66 +++++++++++++++++++
 .../README_EN.md                              | 66 +++++++++++++++++++
 2 files changed, 132 insertions(+)

diff --git a/solution/2400-2499/2475.Number of Unequal Triplets in Array/README.md b/solution/2400-2499/2475.Number of Unequal Triplets in Array/README.md
index 0e1e0fed3d48e..3eac228fbc2c3 100644
--- a/solution/2400-2499/2475.Number of Unequal Triplets in Array/README.md	
+++ b/solution/2400-2499/2475.Number of Unequal Triplets in Array/README.md	
@@ -385,6 +385,72 @@ impl Solution {
 }
 ```
 
+```rust
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn unequal_triplets(nums: Vec<i32>) -> i32 {
+        let cnt = nums.iter().fold(HashMap::new(), |mut map, &n| {
+            *map.entry(n).or_insert(0) += 1;
+            map
+        });
+
+        let mut ans = 0;
+        let n = nums.len();
+        let mut a = 0;
+        for &b in cnt.values() {
+            let c = n - a - b;
+            ans += a * b * c;
+            a += b;
+        }
+
+        ans as i32
+    }
+}
+```
+
+```rust
+impl Solution {
+    pub fn unequal_triplets(nums: Vec<i32>) -> i32 {
+        let mut ans = 0;
+        let mut nums = nums;
+        nums.sort();
+        let n = nums.len();
+
+        for i in 1..n - 1 {
+
+            let mut l = 0;
+            let mut r = i;
+            while l < r {
+                let mid = (l + r) >> 1;
+                if nums[mid] >= nums[i] {
+                    r = mid;
+                } else {
+                    l = mid + 1;
+                }
+            }
+            let j = r;
+
+            let mut l = i + 1;
+            let mut r = n;
+            while l < r {
+                let mid = (l + r) >> 1;
+                if nums[mid] > nums[i] {
+                    r = mid;
+                } else {
+                    l = mid + 1;
+                }
+            }
+            let k = r;
+
+            ans += j * (n - k)
+        } 
+
+        ans as i32
+    }
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/2400-2499/2475.Number of Unequal Triplets in Array/README_EN.md b/solution/2400-2499/2475.Number of Unequal Triplets in Array/README_EN.md
index 554081788416f..d7946c96ba659 100644
--- a/solution/2400-2499/2475.Number of Unequal Triplets in Array/README_EN.md	
+++ b/solution/2400-2499/2475.Number of Unequal Triplets in Array/README_EN.md	
@@ -353,6 +353,72 @@ impl Solution {
 }
 ```
 
+```rust
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn unequal_triplets(nums: Vec<i32>) -> i32 {
+        let cnt = nums.iter().fold(HashMap::new(), |mut map, &n| {
+            *map.entry(n).or_insert(0) += 1;
+            map
+        });
+
+        let mut ans = 0;
+        let n = nums.len();
+        let mut a = 0;
+        for &b in cnt.values() {
+            let c = n - a - b;
+            ans += a * b * c;
+            a += b;
+        }
+
+        ans as i32
+    }
+}
+```
+
+```rust
+impl Solution {
+    pub fn unequal_triplets(nums: Vec<i32>) -> i32 {
+        let mut ans = 0;
+        let mut nums = nums;
+        nums.sort();
+        let n = nums.len();
+
+        for i in 1..n - 1 {
+
+            let mut l = 0;
+            let mut r = i;
+            while l < r {
+                let mid = (l + r) >> 1;
+                if nums[mid] >= nums[i] {
+                    r = mid;
+                } else {
+                    l = mid + 1;
+                }
+            }
+            let j = r;
+
+            let mut l = i + 1;
+            let mut r = n;
+            while l < r {
+                let mid = (l + r) >> 1;
+                if nums[mid] > nums[i] {
+                    r = mid;
+                } else {
+                    l = mid + 1;
+                }
+            }
+            let k = r;
+
+            ans += j * (n - k)
+        } 
+
+        ans as i32
+    }
+}
+```
+
 ### **...**
 
 ```