https://leetcode.cn/problems/number-of-unequal-triplets-in-array

Author: masx200

README.md

@@ -45,6 +45,8 @@ Step 2. Add the dependency
 
 <summary>展开查看</summary>
 
+https://leetcode.cn/problems/number-of-unequal-triplets-in-array
+
 https://leetcode.cn/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance/
 
 https://leetcode.cn/problems/champagne-tower

number-of-unequal-triplets-in-array/index.ts

@@ -0,0 +1,15 @@
+export default function unequalTriplets(nums: number[]): number {
+    nums.sort((a, b) => a - b);
+
+    let ans = 0;
+    let start = 0;
+    const n = nums.length;
+    for (let i = 0; i < n - 1; i++) {
+        const x = nums[i];
+        if (x != nums[i + 1]) {
+            ans += start * (i - start + 1) * (n - 1 - i);
+            start = i + 1;
+        }
+    }
+    return ans;
+}