Merge pull request #1130 from 0xff-dev/1711

Add solution and test-cases for problem 1711

Author: 6boris

leetcode/1701-1800/1711.Count-Good-Meals/README.md

@@ -1,28 +1,30 @@
 # [1711.Count Good Meals][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+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 `10^9 + 7`.
+
+Note that items with different indices are considered different even if they have the same deliciousness value.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: deliciousness = [1,3,5,7,9]
+Output: 4
+Explanation: The good meals are (1,3), (1,7), (3,5) and, (7,9).
+Their respective sums are 4, 8, 8, and 16, all of which are powers of 2.
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Count Good Meals
-```go
 ```
-
+Input: deliciousness = [1,1,1,3,3,3,7]
+Output: 15
+Explanation: The good meals are (1,1) with 3 ways, (1,3) with 9 ways, and (1,7) with 3 ways.
+```
 
 ## 结语
 

leetcode/1701-1800/1711.Count-Good-Meals/Solution.go

@@ -1,5 +1,31 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+const mod = 1000000007
+
+func Solution(deliciousness []int) int {
+	cur := int64(1)
+	cnt := make(map[int64]int)
+	for _, n := range deliciousness {
+		cnt[int64(n)]++
+	}
+	ans := 0
+	for i := 0; i <= 41; i++ {
+		skip := map[int64]struct{}{}
+		for d, n := range cnt {
+			if _, ok := skip[d]; ok {
+				continue
+			}
+			diff := cur - d
+			if v, ok := cnt[diff]; ok {
+				skip[diff] = struct{}{}
+				if diff == d {
+					ans = (ans + n*(n-1)/2) % mod
+				} else {
+					ans = (ans + n*v) % mod
+				}
+			}
+		}
+		cur <<= 1
+	}
+	return ans
 }

leetcode/1701-1800/1711.Count-Good-Meals/Solution_test.go

@@ -10,12 +10,11 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 3, 5, 7, 9}, 4},
+		{"TestCase2", []int{1, 1, 1, 3, 3, 3, 7}, 15},
 	}
 
 	//	开始测试
@@ -30,10 +29,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }