Create 1711-count-good-meals.js

Author: everthis

1711-count-good-meals.js

@@ -0,0 +1,31 @@
+/**
+ * @param {number[]} deliciousness
+ * @return {number}
+ */
+const countPairs = function (deliciousness) {
+  const N = deliciousness.length
+  deliciousness.sort((a, b) => a - b)
+  const mp = {},
+    mod = 10 ** 9 + 7
+  let ret = 0
+  for (let i = 0; i < N; i++) {
+    if (deliciousness[i] !== 0) {
+      let sum = 1 << (32 - __builtin_clz(deliciousness[i]) - 1)
+      ret += mp[sum - deliciousness[i]] || 0
+      ret += mp[(sum << 1) - deliciousness[i]] || 0
+      if (ret >= mod) ret -= mod
+    }
+    if (mp[deliciousness[i]] == null) mp[deliciousness[i]] = 0
+    mp[deliciousness[i]]++
+  }
+  return ret
+}
+
+function __builtin_clz(num) {
+  if (num === 0) return 32
+  return 32 - dec2bin(num).length
+}
+
+function dec2bin(num) {
+  return (num >>> 0).toString(2)
+}