Add solution and test-cases for problem 2894

leetcode/2801-2900/2894.Divisible-And-Non-divisible-Sums-Difference/README.md

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+# [2894.Divisible and Non-divisible Sums Difference][title]
+
+## Description
+You are given positive integers `n` and `m`.
+
+Define two integers as follows:
+
+- `num1`: The sum of all integers in the range `[1, n]` (both **inclusive**) that are **not divisible** by `m`.
+- `num2`: The sum of all integers in the range `[1, n]` (both **inclusive**) that are **divisible** by `m`.
+
+Return the integer `num1 - num2`.
+
+**Example 1:**
+
+```
+Input: n = 10, m = 3
+Output: 19
+Explanation: In the given example:
+- Integers in the range [1, 10] that are not divisible by 3 are [1,2,4,5,7,8,10], num1 is the sum of those integers = 37.
+- Integers in the range [1, 10] that are divisible by 3 are [3,6,9], num2 is the sum of those integers = 18.
+We return 37 - 18 = 19 as the answer.
+```
+
+**Example 2:**
+
+```
+Input: n = 5, m = 6
+Output: 15
+Explanation: In the given example:
+- Integers in the range [1, 5] that are not divisible by 6 are [1,2,3,4,5], num1 is the sum of those integers = 15.
+- Integers in the range [1, 5] that are divisible by 6 are [], num2 is the sum of those integers = 0.
+We return 15 - 0 = 15 as the answer.
+```
+
+**Example 3:**
+
+```
+Input: n = 5, m = 1
+Output: -15
+Explanation: In the given example:
+- Integers in the range [1, 5] that are not divisible by 1 are [], num1 is the sum of those integers = 0.
+- Integers in the range [1, 5] that are divisible by 1 are [1,2,3,4,5], num2 is the sum of those integers = 15.
+We return 0 - 15 = -15 as the answer.
+```
+
+## 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/divisible-and-non-divisible-sums-difference
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2801-2900/2894.Divisible-And-Non-divisible-Sums-Difference/Solution.go

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+package Solution
+
+func Solution(n int, m int) int {
+	sum := 0
+	for i := 1; i <= n; i++ {
+		if i%m != 0 {
+			sum += i
+			continue
+		}
+		sum -= i
+	}
+	return sum
+}

leetcode/2801-2900/2894.Divisible-And-Non-divisible-Sums-Difference/Solution_test.go

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+package Solution
+
+import (
+	"reflect"
+	"strconv"
+	"testing"
+)
+
+func TestSolution(t *testing.T) {
+	//	测试用例
+	cases := []struct {
+		name   string
+		n, m   int
+		expect int
+	}{
+		{"TestCase1", 10, 3, 19},
+		{"TestCase2", 5, 6, 15},
+		{"TestCase3", 5, 1, -15},
+	}
+
+	//	开始测试
+	for i, c := range cases {
+		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
+			got := Solution(c.n, c.m)
+			if !reflect.DeepEqual(got, c.expect) {
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.n, c.m)
+			}
+		})
+	}
+}
+
+// 压力测试
+func BenchmarkSolution(b *testing.B) {
+}
+
+// 使用案列
+func ExampleSolution() {
+}