Create 2367-count-number-of-bad-pairs.js

Author: everthis

2367-count-number-of-bad-pairs.js

@@ -0,0 +1,15 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+const countBadPairs = function (nums) {
+  let cnt = 0
+  const n = nums.length
+  const mp = {}
+  for (let i = 0; i < n; i++) {
+    const prev = mp[i - nums[i]] || 0
+    cnt += prev
+    mp[i - nums[i]] = prev + 1
+  }
+  return (n * (n - 1)) / 2 - cnt
+}