feat: add solutions to lc problem: No.2178 (#3986)

No.2178.Maximum Split of Positive Even Integers

Author: yanglbme

solution/2100-2199/2178.Maximum Split of Positive Even Integers/README.md

@@ -75,11 +75,11 @@ tags:
 
 ### 方法一：贪心
 
-如果 $finalSum$ 是奇数，那么无法拆分成若干个互不相同的正偶数之和，直接返回空数组。
+如果 $\textit{finalSum}$ 是奇数，那么无法拆分成若干个互不相同的正偶数之和，直接返回空数组。
 
-否则，我们可以贪心地按照 $2, 4, 6, \cdots$ 的顺序拆分 $finalSum$，直到 $finalSum$ 无法再拆分出一个不同的正偶数为止，此时我们将剩余的 $finalSum$ 加到最后一个正偶数上即可。
+否则，我们可以贪心地按照 $2, 4, 6, \cdots$ 的顺序拆分 $\textit{finalSum}$，直到 $\textit{finalSum}$ 无法再拆分出一个不同的正偶数为止，此时我们将剩余的 $\textit{finalSum}$ 加到最后一个正偶数上即可。
 
-时间复杂度 $O(\sqrt{finalSum})$，忽略答案数组的空间消耗，空间复杂度 $O(1)$。
+时间复杂度 $O(\sqrt{\textit{finalSum}})$，忽略答案数组的空间消耗，空间复杂度 $O(1)$。
 
 <!-- tabs:start -->
 
@@ -88,13 +88,13 @@ tags:
 ```python
 class Solution:
     def maximumEvenSplit(self, finalSum: int) -> List[int]:
-        if finalSum % 2:
+        if finalSum & 1:
             return []
-        i = 2
         ans = []
+        i = 2
         while i <= finalSum:
-            ans.append(i)
             finalSum -= i
+            ans.append(i)
             i += 2
         ans[-1] += finalSum
         return ans
@@ -126,7 +126,9 @@ class Solution {
 public:
     vector<long long> maximumEvenSplit(long long finalSum) {
         vector<long long> ans;
-        if (finalSum % 2) return ans;
+        if (finalSum % 2) {
+            return ans;
+        }
         for (long long i = 2; i <= finalSum; i += 2) {
             ans.push_back(i);
             finalSum -= i;
@@ -170,6 +172,29 @@ function maximumEvenSplit(finalSum: number): number[] {
 }
 ```
 
+#### Rust
+
+```rust
+impl Solution {
+    pub fn maximum_even_split(mut final_sum: i64) -> Vec<i64> {
+        let mut ans = Vec::new();
+        if final_sum % 2 != 0 {
+            return ans;
+        }
+        let mut i = 2;
+        while i <= final_sum {
+            ans.push(i);
+            final_sum -= i;
+            i += 2;
+        }
+        if let Some(last) = ans.last_mut() {
+            *last += final_sum;
+        }
+        ans
+    }
+}
+```
+
 #### C#
 
 ```cs

solution/2100-2199/2178.Maximum Split of Positive Even Integers/README_EN.md

@@ -53,7 +53,7 @@ Thus, we return an empty array.
 <pre>
 <strong>Input:</strong> finalSum = 28
 <strong>Output:</strong> [6,8,2,12]
-<strong>Explanation:</strong> The following are valid splits: <code>(2 + 26)</code>, <code>(6 + 8 + 2 + 12)</code>, and <code>(4 + 24)</code>. 
+<strong>Explanation:</strong> The following are valid splits: <code>(2 + 26)</code>, <code>(6 + 8 + 2 + 12)</code>, and <code>(4 + 24)</code>.
 <code>(6 + 8 + 2 + 12)</code> has the maximum number of integers, which is 4. Thus, we return [6,8,2,12].
 Note that [10,2,4,12], [6,2,4,16], etc. are also accepted.
 </pre>
@@ -71,7 +71,13 @@ Note that [10,2,4,12], [6,2,4,16], etc. are also accepted.
 
 <!-- solution:start -->
 
-### Solution 1
+### Solution 1: Greedy
+
+If $\textit{finalSum}$ is odd, it cannot be split into the sum of several distinct positive even integers, so we directly return an empty array.
+
+Otherwise, we can greedily split $\textit{finalSum}$ in the order of $2, 4, 6, \cdots$, until $\textit{finalSum}$ can no longer be split into a different positive even integer. At this point, we add the remaining $\textit{finalSum}$ to the last positive even integer.
+
+The time complexity is $O(\sqrt{\textit{finalSum}})$, and ignoring the space consumption of the answer array, the space complexity is $O(1)$.
 
 <!-- tabs:start -->
 
@@ -80,13 +86,13 @@ Note that [10,2,4,12], [6,2,4,16], etc. are also accepted.
 ```python
 class Solution:
     def maximumEvenSplit(self, finalSum: int) -> List[int]:
-        if finalSum % 2:
+        if finalSum & 1:
             return []
-        i = 2
         ans = []
+        i = 2
         while i <= finalSum:
-            ans.append(i)
             finalSum -= i
+            ans.append(i)
             i += 2
         ans[-1] += finalSum
         return ans
@@ -118,7 +124,9 @@ class Solution {
 public:
     vector<long long> maximumEvenSplit(long long finalSum) {
         vector<long long> ans;
-        if (finalSum % 2) return ans;
+        if (finalSum % 2) {
+            return ans;
+        }
         for (long long i = 2; i <= finalSum; i += 2) {
             ans.push_back(i);
             finalSum -= i;
@@ -162,6 +170,29 @@ function maximumEvenSplit(finalSum: number): number[] {
 }
 ```
 
+#### Rust
+
+```rust
+impl Solution {
+    pub fn maximum_even_split(mut final_sum: i64) -> Vec<i64> {
+        let mut ans = Vec::new();
+        if final_sum % 2 != 0 {
+            return ans;
+        }
+        let mut i = 2;
+        while i <= final_sum {
+            ans.push(i);
+            final_sum -= i;
+            i += 2;
+        }
+        if let Some(last) = ans.last_mut() {
+            *last += final_sum;
+        }
+        ans
+    }
+}
+```
+
 #### C#
 
 ```cs

solution/2100-2199/2178.Maximum Split of Positive Even Integers/Solution.cpp

@@ -2,12 +2,14 @@ class Solution {
 public:
     vector<long long> maximumEvenSplit(long long finalSum) {
         vector<long long> ans;
-        if (finalSum % 2) return ans;
+        if (finalSum % 2) {
+            return ans;
+        }
         for (long long i = 2; i <= finalSum; i += 2) {
             ans.push_back(i);
             finalSum -= i;
         }
         ans.back() += finalSum;
         return ans;
     }
-};
+};

solution/2100-2199/2178.Maximum Split of Positive Even Integers/Solution.py

@@ -1,12 +1,12 @@
 class Solution:
     def maximumEvenSplit(self, finalSum: int) -> List[int]:
-        if finalSum % 2:
+        if finalSum & 1:
             return []
-        i = 2
         ans = []
+        i = 2
         while i <= finalSum:
-            ans.append(i)
             finalSum -= i
+            ans.append(i)
             i += 2
         ans[-1] += finalSum
         return ans

solution/2100-2199/2178.Maximum Split of Positive Even Integers/Solution.rs

@@ -0,0 +1,18 @@
+impl Solution {
+    pub fn maximum_even_split(mut final_sum: i64) -> Vec<i64> {
+        let mut ans = Vec::new();
+        if final_sum % 2 != 0 {
+            return ans;
+        }
+        let mut i = 2;
+        while i <= final_sum {
+            ans.push(i);
+            final_sum -= i;
+            i += 2;
+        }
+        if let Some(last) = ans.last_mut() {
+            *last += final_sum;
+        }
+        ans
+    }
+}