Add solution and test-cases for problem 1497

leetcode/1401-1500/1497.Check-If-Array-Pairs-Are-Divisible-by-k/README.md

@@ -0,0 +1,39 @@
+# [1497.Check If Array Pairs Are Divisible by k][title]
+
+## Description
+Given an array of integers `arr` of even length `n` and an integer `k`.
+
+We want to divide the array into exactly `n / 2` pairs such that the sum of each pair is divisible by `k`.
+
+Return `true` If you can find a way to do that or `false` otherwise.
+
+**Example 1:**
+
+```
+Input: arr = [1,2,3,4,5,10,6,7,8,9], k = 5
+Output: true
+Explanation: Pairs are (1,9),(2,8),(3,7),(4,6) and (5,10).
+```
+
+**Example 2:**
+
+```
+Input: arr = [1,2,3,4,5,6], k = 7
+Output: true
+Explanation: Pairs are (1,6),(2,5) and(3,4).
+```
+
+**Example 3:**
+
+```
+Input: arr = [1,2,3,4,5,6], k = 10
+Output: false
+Explanation: You can try all possible pairs to see that there is no way to divide arr into 3 pairs each with sum divisible by 10.
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
+
+[title]: https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/1401-1500/1497.Check-If-Array-Pairs-Are-Divisible-by-k/Solution.go

@@ -1,5 +1,21 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(arr []int, k int) bool {
+	count := make([]int, k)
+	for _, n := range arr {
+		t := n % k
+		if n < 0 {
+			t = k - (-n % k)
+			if t == k {
+				t = 0
+			}
+		}
+		count[t]++
+	}
+	for i := 1; i < k; i++ {
+		if count[i] != count[k-i] {
+			return false
+		}
+	}
+	return count[0]%2 == 0
 }

leetcode/1401-1500/1497.Check-If-Array-Pairs-Are-Divisible-by-k/Solution_test.go

@@ -10,30 +10,31 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
+		arr    []int
+		k      int
 		expect bool
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 2, 3, 4, 5, 10, 6, 7, 8, 9}, 5, true},
+		{"TestCase2", []int{1, 2, 3, 4, 5, 6}, 7, true},
+		{"TestCase3", []int{1, 2, 3, 4, 5, 6}, 10, false},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.arr, c.k)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.arr, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }