add 1711

fishercoder1534 · fishercoder1534 · commit 412e668463c3 · 2021-01-06T15:48:06.000-08:00
diff --git a/README.md b/README.md
@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ &#9733;
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1711|[Count Good Meals](https://leetcode.com/problems/count-good-meals/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1711.java) ||Medium|Array, HashTable, Two Pointers|
 |1710|[Maximum Units on a Truck](https://leetcode.com/problems/maximum-units-on-a-truck/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1710.java) ||Easy|Greedy, Sort|
 |1708|[Largest Subarray Length K](https://leetcode.com/problems/largest-subarray-length-k/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1708.java) ||Easy|Array, Greedy|
 |1704|[Determine if String Halves Are Alike](https://leetcode.com/problems/determine-if-string-halves-are-alike/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1704.java) ||Easy|String|
diff --git a/src/main/java/com/fishercoder/solutions/_1711.java b/src/main/java/com/fishercoder/solutions/_1711.java
@@ -0,0 +1,28 @@
+package com.fishercoder.solutions;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class _1711 {
+    public static class Solution1 {
+        private static final long MODUALR = 1000000007;
+
+        public int countPairs(int[] deliciousness) {
+            Map<Integer, Integer> map = new HashMap<>();
+            long pairs = 0;
+            for (int i = 0; i < deliciousness.length; i++) {
+                int power = 1;
+                for (int j = 0; j < 22; j++) {//we only need to go up to 21 since one of the constraints is: 0 <= deliciousness[i] <= 2 to the power of 20
+                    if (map.containsKey(power - deliciousness[i])) {
+                        pairs += map.get(power - deliciousness[i]);
+                        pairs %= MODUALR;
+                    }
+                    power *= 2;
+                }
+                map.put(deliciousness[i], map.getOrDefault(deliciousness[i], 0) + 1);
+            }
+            return (int) pairs;
+        }
+
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1711Test.java b/src/test/java/com/fishercoder/_1711Test.java
@@ -0,0 +1,36 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1711;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1711Test {
+    private static _1711.Solution1 solution1;
+    private static int[] deliciousness;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1711.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        deliciousness = new int[]{1, 3, 5, 7, 9};
+        assertEquals(4, solution1.countPairs(deliciousness));
+    }
+
+    @Test
+    public void test2() {
+        deliciousness = new int[]{1, 1, 1, 3, 3, 3, 7};
+        assertEquals(15, solution1.countPairs(deliciousness));
+    }
+
+    @Test
+    public void test3() {
+        deliciousness = new int[]{64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64};
+        assertEquals(528, solution1.countPairs(deliciousness));
+    }
+
+}
