Create 1396-count-number-of-teams.js

Author: everthis

1396-count-number-of-teams.js

@@ -0,0 +1,20 @@
+/**
+ * @param {number[]} rating
+ * @return {number}
+ */
+const numTeams = function(rating) {
+  let res = 0
+  for(let i = 1, n = rating.length; i < n - 1; i++) {
+    const less = Array(2).fill(0), greater = Array(2).fill(0)
+    for(let j = 0; j < n; j++) {
+      if(rating[i] > rating[j]) {
+        less[j < i ? 0 : 1]++
+      }
+      if(rating[i] < rating[j]) {
+        greater[j > i ? 0 : 1]++
+      }
+    }
+    res += less[0] * greater[0] + less[1] * greater[1]
+  }
+  return res
+};