Add solution #1711

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,493 LeetCode solutions in JavaScript
+# 1,494 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1318,6 +1318,7 @@
 1706|[Where Will the Ball Fall](./solutions/1706-where-will-the-ball-fall.js)|Medium|
 1707|[Maximum XOR With an Element From Array](./solutions/1707-maximum-xor-with-an-element-from-array.js)|Hard|
 1710|[Maximum Units on a Truck](./solutions/1710-maximum-units-on-a-truck.js)|Easy|
+1711|[Count Good Meals](./solutions/1711-count-good-meals.js)|Medium|
 1716|[Calculate Money in Leetcode Bank](./solutions/1716-calculate-money-in-leetcode-bank.js)|Easy|
 1718|[Construct the Lexicographically Largest Valid Sequence](./solutions/1718-construct-the-lexicographically-largest-valid-sequence.js)|Medium|
 1726|[Tuple with Same Product](./solutions/1726-tuple-with-same-product.js)|Medium|

solutions/1711-count-good-meals.js

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+/**
+ * 1711. Count Good Meals
+ * https://leetcode.com/problems/count-good-meals/
+ * Difficulty: Medium
+ *
+ * A good meal is a meal that contains exactly two different food items with a sum of deliciousness
+ * equal to a power of two.
+ *
+ * You can pick any two different foods to make a good meal.
+ *
+ * Given an array of integers deliciousness where deliciousness[i] is the deliciousness of the
+ * ith item of food, return the number of different good meals you can make from this list
+ * modulo 109 + 7.
+ *
+ * Note that items with different indices are considered different even if they have the same
+ * deliciousness value.
+ */
+
+/**
+ * @param {number[]} deliciousness
+ * @return {number}
+ */
+var countPairs = function(deliciousness) {
+  const MOD = 1e9 + 7;
+  const frequency = new Map();
+  let result = 0;
+
+  for (const value of deliciousness) {
+    for (let power = 1; power <= 1 << 21; power <<= 1) {
+      const complement = power - value;
+      if (frequency.has(complement)) {
+        result = (result + frequency.get(complement)) % MOD;
+      }
+    }
+    frequency.set(value, (frequency.get(value) || 0) + 1);
+  }
+
+  return result;
+};