Add solution and test-cases for problem 2698

Author: 0xff-dev

leetcode/2601-2700/2698.Find-the-Punishment-Number-of-an-Integer/README.md

@@ -0,0 +1,41 @@
+# [2698.Find the Punishment Number of an Integer][title]
+
+## Description
+Given a positive integer `n`, return the **punishment number** of `n`.
+
+The **punishment number** of `n` is defined as the sum of the squares of all integers `i` such that:
+
+- `1 <= i <= n`
+- The decimal representation of `i * i` can be partitioned into contiguous substrings such that the sum of the integer values of these substrings equals `i`.
+
+**Example 1:**
+
+```
+Input: n = 10
+Output: 182
+Explanation: There are exactly 3 integers i in the range [1, 10] that satisfy the conditions in the statement:
+- 1 since 1 * 1 = 1
+- 9 since 9 * 9 = 81 and 81 can be partitioned into 8 and 1 with a sum equal to 8 + 1 == 9.
+- 10 since 10 * 10 = 100 and 100 can be partitioned into 10 and 0 with a sum equal to 10 + 0 == 10.
+Hence, the punishment number of 10 is 1 + 81 + 100 = 182
+```
+
+**Example 2:**
+
+```
+Input: n = 37
+Output: 1478
+Explanation: There are exactly 4 integers i in the range [1, 37] that satisfy the conditions in the statement:
+- 1 since 1 * 1 = 1. 
+- 9 since 9 * 9 = 81 and 81 can be partitioned into 8 + 1. 
+- 10 since 10 * 10 = 100 and 100 can be partitioned into 10 + 0. 
+- 36 since 36 * 36 = 1296 and 1296 can be partitioned into 1 + 29 + 6.
+Hence, the punishment number of 37 is 1 + 81 + 100 + 1296 = 1478
+```
+
+## 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/find-the-punishment-number-of-an-integer
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2601-2700/2698.Find-the-Punishment-Number-of-an-Integer/Solution.go

@@ -1,5 +1,26 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func ok(n, target int) bool {
+	if n == target {
+		return true
+	}
+	base := 10
+	for ; base <= n; base *= 10 {
+		mod := n % base
+		if ok(n/base, target-mod) {
+			return true
+		}
+	}
+	return false
+}
+func Solution(n int) int {
+	ans := 0
+	for i := 1; i <= n; i++ {
+		x := i * i
+		res := ok(x, i)
+		if res {
+			ans += x
+		}
+	}
+	return ans
 }

leetcode/2601-2700/2698.Find-the-Punishment-Number-of-an-Integer/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", 10, 182},
+		{"TestCase2", 37, 1478},
 	}
 
 	//	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() {
 }