Create 1688-count-of-matches-in-tournament.js

Author: everthis

1688-count-of-matches-in-tournament.js

@@ -0,0 +1,23 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var numberOfMatches = function(n) {
+  const obj = { res: 0 }
+  helper(n, obj)
+  return obj.res
+};
+
+function helper(num, obj) {
+  if(num <= 1) return
+  const odd = num % 2 === 1
+  if(odd) {
+    const tmp = Math.floor((num - 1) / 2) 
+    obj.res += tmp
+    helper(tmp + 1, obj)
+  } else {
+    const tmp = Math.floor(num / 2) 
+    obj.res += tmp
+    helper(tmp, obj)
+  }
+}