+ problem 1330

Author: fruit-in

Problemset/1330-Reverse Subarray To Maximize Array Value/README.md

@@ -0,0 +1,63 @@
+# 1330. Reverse Subarray To Maximize Array Value
+You are given an integer array `nums`. The *value* of this array is defined as the sum of `|nums[i] - nums[i + 1]|` for all `0 <= i < nums.length - 1`.
+
+You are allowed to select any subarray of the given array and reverse it. You can perform this operation **only once**.
+
+Find maximum possible value of the final array.
+
+#### Example 1:
+<pre>
+<strong>Input:</strong> nums = [2,3,1,5,4]
+<strong>Output:</strong> 10
+<strong>Explanation:</strong> By reversing the subarray [3,1,5] the array becomes [2,5,1,3,4] whose value is 10.
+</pre>
+
+#### Example 2:
+<pre>
+<strong>Input:</strong> nums = [2,4,9,24,2,1,10]
+<strong>Output:</strong> 68
+</pre>
+
+#### Constraints:
+* <code>1 <= nums.length <= 3 * 10<sup>4</sup></code>
+* <code>-10<sup>5</sup> <= nums[i] <= 10<sup>5</sup></code>
+
+## Solutions (Rust)
+
+### 1. Solution
+```Rust
+impl Solution {
+    pub fn max_value_after_reverse(nums: Vec<i32>) -> i32 {
+        let origin = (1..nums.len())
+            .map(|i| (nums[i] - nums[i - 1]).abs())
+            .sum::<i32>();
+        let mut max_num = nums[0].min(nums[1]);
+        let mut min_num = nums[0].max(nums[1]);
+        let mut ret = origin;
+
+        for i in 1..nums.len() - 1 {
+            let a = nums[i - 1];
+            let b = nums[i];
+            let c = nums[i + 1];
+
+            ret = ret.max(origin + (c - nums[0]).abs() - (c - b).abs());
+            ret = ret.max(origin + (a - nums.last().unwrap()).abs() - (b - a).abs());
+
+            let x = b.max(c);
+            let y = b.min(c);
+
+            if x < max_num {
+                ret = ret.max(origin + 2 * max_num - 2 * x);
+            }
+            if y > min_num {
+                ret = ret.max(origin + 2 * y - 2 * min_num);
+            }
+
+            max_num = max_num.max(y);
+            min_num = min_num.min(x);
+        }
+
+        ret
+    }
+}
+```

Problemset/1330-Reverse Subarray To Maximize Array Value/README_CN.md

@@ -0,0 +1,63 @@
+# 1330. 翻转子数组得到最大的数组值
+给你一个整数数组 `nums` 。「数组值」定义为所有满足 `0 <= i < nums.length-1` 的 `|nums[i]-nums[i+1]|` 的和。
+
+你可以选择给定数组的任意子数组，并将该子数组翻转。但你只能执行这个操作 **一次** 。
+
+请你找到可行的最大 **数组值** 。
+
+#### 示例 1:
+<pre>
+<strong>输入:</strong> nums = [2,3,1,5,4]
+<strong>输出:</strong> 10
+<strong>解释:</strong> 通过翻转子数组 [3,1,5] ，数组变成 [2,5,1,3,4] ，数组值为 10 。
+</pre>
+
+#### 示例 2:
+<pre>
+<strong>输入:</strong> nums = [2,4,9,24,2,1,10]
+<strong>输出:</strong> 68
+</pre>
+
+#### 提示:
+* <code>1 <= nums.length <= 3 * 10<sup>4</sup></code>
+* <code>-10<sup>5</sup> <= nums[i] <= 10<sup>5</sup></code>
+
+## 题解 (Rust)
+
+### 1. 题解
+```Rust
+impl Solution {
+    pub fn max_value_after_reverse(nums: Vec<i32>) -> i32 {
+        let origin = (1..nums.len())
+            .map(|i| (nums[i] - nums[i - 1]).abs())
+            .sum::<i32>();
+        let mut max_num = nums[0].min(nums[1]);
+        let mut min_num = nums[0].max(nums[1]);
+        let mut ret = origin;
+
+        for i in 1..nums.len() - 1 {
+            let a = nums[i - 1];
+            let b = nums[i];
+            let c = nums[i + 1];
+
+            ret = ret.max(origin + (c - nums[0]).abs() - (c - b).abs());
+            ret = ret.max(origin + (a - nums.last().unwrap()).abs() - (b - a).abs());
+
+            let x = b.max(c);
+            let y = b.min(c);
+
+            if x < max_num {
+                ret = ret.max(origin + 2 * max_num - 2 * x);
+            }
+            if y > min_num {
+                ret = ret.max(origin + 2 * y - 2 * min_num);
+            }
+
+            max_num = max_num.max(y);
+            min_num = min_num.min(x);
+        }
+
+        ret
+    }
+}
+```

Problemset/1330-Reverse Subarray To Maximize Array Value/Solution.rs

@@ -0,0 +1,34 @@
+impl Solution {
+    pub fn max_value_after_reverse(nums: Vec<i32>) -> i32 {
+        let origin = (1..nums.len())
+            .map(|i| (nums[i] - nums[i - 1]).abs())
+            .sum::<i32>();
+        let mut max_num = nums[0].min(nums[1]);
+        let mut min_num = nums[0].max(nums[1]);
+        let mut ret = origin;
+
+        for i in 1..nums.len() - 1 {
+            let a = nums[i - 1];
+            let b = nums[i];
+            let c = nums[i + 1];
+
+            ret = ret.max(origin + (c - nums[0]).abs() - (c - b).abs());
+            ret = ret.max(origin + (a - nums.last().unwrap()).abs() - (b - a).abs());
+
+            let x = b.max(c);
+            let y = b.min(c);
+
+            if x < max_num {
+                ret = ret.max(origin + 2 * max_num - 2 * x);
+            }
+            if y > min_num {
+                ret = ret.max(origin + 2 * y - 2 * min_num);
+            }
+
+            max_num = max_num.max(y);
+            min_num = min_num.min(x);
+        }
+
+        ret
+    }
+}

README.md

@@ -770,6 +770,7 @@
 [1325][1325l]|[Delete Leaves With a Given Value][1325]                                              |![py]
 [1328][1328l]|[Break a Palindrome][1328]                                                            |![rb]  ![rs]
 [1329][1329l]|[Sort the Matrix Diagonally][1329]                                                    |![rb]  ![rs]
+[1330][1330l]|[Reverse Subarray To Maximize Array Value][1330]                                      |![rs]
 [1331][1331l]|[Rank Transform of an Array][1331]                                                    |![py]
 [1332][1332l]|[Remove Palindromic Subsequences][1332]                                               |![py]
 [1333][1333l]|[Filter Restaurants by Vegan-Friendly, Price and Distance][1333]                      |![rb]  ![rs]
@@ -2165,6 +2166,7 @@
 [1325]:Problemset/1325-Delete%20Leaves%20With%20a%20Given%20Value/README.md#1325-delete-leaves-with-a-given-value
 [1328]:Problemset/1328-Break%20a%20Palindrome/README.md#1328-break-a-palindrome
 [1329]:Problemset/1329-Sort%20the%20Matrix%20Diagonally/README.md#1329-sort-the-matrix-diagonally
+[1330]:Problemset/1330-Reverse%20Subarray%20To%20Maximize%20Array%20Value/README.md#1330-reverse-subarray-to-maximize-array-value
 [1331]:Problemset/1331-Rank%20Transform%20of%20an%20Array/README.md#1331-rank-transform-of-an-array
 [1332]:Problemset/1332-Remove%20Palindromic%20Subsequences/README.md#1332-remove-palindromic-subsequences
 [1333]:Problemset/1333-Filter%20Restaurants%20by%20Vegan-Friendly,%20Price%20and%20Distance/README.md#1333-filter-restaurants-by-vegan-friendly-price-and-distance
@@ -3559,6 +3561,7 @@
 [1325l]:https://leetcode.com/problems/delete-leaves-with-a-given-value/
 [1328l]:https://leetcode.com/problems/break-a-palindrome/
 [1329l]:https://leetcode.com/problems/sort-the-matrix-diagonally/
+[1330l]:https://leetcode.com/problems/reverse-subarray-to-maximize-array-value/
 [1331l]:https://leetcode.com/problems/rank-transform-of-an-array/
 [1332l]:https://leetcode.com/problems/remove-palindromic-subsequences/
 [1333l]:https://leetcode.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance/

README_CN.md

@@ -770,6 +770,7 @@
 [1325][1325l]|[删除给定值的叶子节点][1325]                              |![py]
 [1328][1328l]|[破坏回文串][1328]                                        |![rb]  ![rs]
 [1329][1329l]|[将矩阵按对角线排序][1329]                                |![rb]  ![rs]
+[1330][1330l]|[翻转子数组得到最大的数组值][1330]                        |![rs]
 [1331][1331l]|[数组序号转换][1331]                                      |![py]
 [1332][1332l]|[删除回文子序列][1332]                                    |![py]
 [1333][1333l]|[餐厅过滤器][1333]                                        |![rb]  ![rs]
@@ -2165,6 +2166,7 @@
 [1325]:Problemset/1325-Delete%20Leaves%20With%20a%20Given%20Value/README_CN.md#1325-删除给定值的叶子节点
 [1328]:Problemset/1328-Break%20a%20Palindrome/README_CN.md#1328-破坏回文串
 [1329]:Problemset/1329-Sort%20the%20Matrix%20Diagonally/README_CN.md#1329-将矩阵按对角线排序
+[1330]:Problemset/1330-Reverse%20Subarray%20To%20Maximize%20Array%20Value/README_CN.md#1330-翻转子数组得到最大的数组值
 [1331]:Problemset/1331-Rank%20Transform%20of%20an%20Array/README_CN.md#1331-数组序号转换
 [1332]:Problemset/1332-Remove%20Palindromic%20Subsequences/README_CN.md#1332-删除回文子序列
 [1333]:Problemset/1333-Filter%20Restaurants%20by%20Vegan-Friendly,%20Price%20and%20Distance/README_CN.md#1333-餐厅过滤器
@@ -3559,6 +3561,7 @@
 [1325l]:https://leetcode.cn/problems/delete-leaves-with-a-given-value/
 [1328l]:https://leetcode.cn/problems/break-a-palindrome/
 [1329l]:https://leetcode.cn/problems/sort-the-matrix-diagonally/
+[1330l]:https://leetcode.cn/problems/reverse-subarray-to-maximize-array-value/
 [1331l]:https://leetcode.cn/problems/rank-transform-of-an-array/
 [1332l]:https://leetcode.cn/problems/remove-palindromic-subsequences/
 [1333l]:https://leetcode.cn/problems/filter-restaurants-by-vegan-friendly-price-and-distance/