feat: add solutions to leetcode and lcof problems

Author: yanglbme

README.md

@@ -58,6 +58,7 @@
 1. [合并两个有序数组](/solution/0000-0099/0088.Merge%20Sorted%20Array/README.md)
 1. [寻找旋转排序数组中的最小值](/solution/0100-0199/0153.Find%20Minimum%20in%20Rotated%20Sorted%20Array/README.md)
 1. [寻找旋转排序数组中的最小值 II](/solution/0100-0199/0154.Find%20Minimum%20in%20Rotated%20Sorted%20Array%20II/README.md)
+1. [除自身以外数组的乘积](/solution/0200-0299/0238.Product%20of%20Array%20Except%20Self/README.md)
 
 ### 字符串
 

README_EN.md

@@ -57,6 +57,7 @@ Complete solutions to [LeetCode](https://leetcode-cn.com/problemset/all/), [LCOF
 1. [Merge Sorted Array](/solution/0000-0099/0088.Merge%20Sorted%20Array/README_EN.md)
 1. [Find Minimum in Rotated Sorted Array](/solution/0100-0199/0153.Find%20Minimum%20in%20Rotated%20Sorted%20Array/README_EN.md)
 1. [Find Minimum in Rotated Sorted Array II](/solution/0100-0199/0154.Find%20Minimum%20in%20Rotated%20Sorted%20Array%20II/README_EN.md)
+1. [Product of Array Except Self](/solution/0200-0299/0238.Product%20of%20Array%20Except%20Self/README_EN.md)
 
 ### Strings
 

lcof/面试题66. 构建乘积数组/README.md

@@ -33,17 +33,16 @@
 ```python
 class Solution:
     def constructArr(self, a: List[int]) -> List[int]:
-        if not a:
-            return []
-        dp1 = [1 for i in a]
-        dp2 = [1 for i in a]
         n = len(a)
-        dp1[0], dp2[n - 1] = a[0], a[n - 1]
-        for i in range(1, n):
-            dp1[i] = dp1[i - 1] * a[i]
-        for i in range(n - 2, -1, -1):
-            dp2[i] = dp2[i + 1] * a[i]
-        return [(1 if i - 1 < 0 else dp1[i - 1]) * (1 if i + 1 >= n else dp2[i + 1]) for i in range(0, n)]
+        output = [1 for _ in a]
+        left = right = 1
+        for i in range(n):
+            output[i] = left
+            left *= a[i]
+        for i in range(n - 1, -1, -1):
+            output[i] *= right
+            right *= a[i]
+        return output
 ```
 
 ### **Java**
@@ -53,25 +52,17 @@ class Solution:
 ```java
 class Solution {
     public int[] constructArr(int[] a) {
-        if (a == null || a.length == 0) {
-            return new int[0];
-        }
         int n = a.length;
-        int[] dp1 = new int[n];
-        int[] dp2 = new int[n];
-        dp1[0] = a[0];
-        dp2[n - 1] = a[n - 1];
-        for (int i = 1; i < n; ++i) {
-            dp1[i] = dp1[i - 1] * a[i];
-        }
-        for (int i = n - 2; i >= 0; --i) {
-            dp2[i] = dp2[i + 1] * a[i];
+        int[] output = new int[n];
+        for (int i = 0, left = 1; i < n; ++i) {
+            output[i] = left;
+            left *= a[i];
         }
-        int[] res = new int[n];
-        for (int i = 0; i < n; ++i) {
-            res[i] = (i - 1 < 0 ? 1 : dp1[i - 1]) * (i + 1 >= n ? 1 : dp2[i + 1]);
+        for (int i = n - 1, right = 1; i >= 0; --i) {
+            output[i] *= right;
+            right *= a[i];
         }
-        return res;
+        return output;
     }
 }
 ```
@@ -84,18 +75,17 @@ class Solution {
  * @return {number[]}
  */
 var constructArr = function (a) {
-  let pre = new Array(a.length + 1).fill(1);
-  pre[0] = 1;
-  let res = new Array(a.length).fill(1);
-  for (let i = 1; i <= a.length; i++) {
-    pre[i] = a[i - 1] * pre[i - 1];
+  const n = a.length;
+  let output = new Array(n);
+  for (let i = 0, left = 1; i < n; ++i) {
+    output[i] = left;
+    left *= a[i];
   }
-  let cur = 1;
-  for (let i = a.length - 1; i >= 0; i--) {
-    res[i] = pre[i] * cur;
-    cur *= a[i];
+  for (let i = n - 1, right = 1; i >= 0; --i) {
+    output[i] *= right;
+    right *= a[i];
   }
-  return res;
+  return output;
 };
 ```
 

lcof/面试题66. 构建乘积数组/Solution.java

@@ -1,23 +1,15 @@
 class Solution {
     public int[] constructArr(int[] a) {
-        if (a == null || a.length == 0) {
-            return new int[0];
-        }
         int n = a.length;
-        int[] dp1 = new int[n];
-        int[] dp2 = new int[n];
-        dp1[0] = a[0];
-        dp2[n - 1] = a[n - 1];
-        for (int i = 1; i < n; ++i) {
-            dp1[i] = dp1[i - 1] * a[i];
-        }
-        for (int i = n - 2; i >= 0; --i) {
-            dp2[i] = dp2[i + 1] * a[i];
+        int[] output = new int[n];
+        for (int i = 0, left = 1; i < n; ++i) {
+            output[i] = left;
+            left *= a[i];
         }
-        int[] res = new int[n];
-        for (int i = 0; i < n; ++i) {
-            res[i] = (i - 1 < 0 ? 1 : dp1[i - 1]) * (i + 1 >= n ? 1 : dp2[i + 1]);
+        for (int i = n - 1, right = 1; i >= 0; --i) {
+            output[i] *= right;
+            right *= a[i];
         }
-        return res;
+        return output;
     }
 }

lcof/面试题66. 构建乘积数组/Solution.js

@@ -3,16 +3,15 @@
  * @return {number[]}
  */
 var constructArr = function (a) {
-  let pre = new Array(a.length + 1).fill(1);
-  pre[0] = 1;
-  let res = new Array(a.length).fill(1);
-  for (let i = 1; i <= a.length; i++) {
-    pre[i] = a[i - 1] * pre[i - 1];
+  const n = a.length;
+  let output = new Array(n);
+  for (let i = 0, left = 1; i < n; ++i) {
+    output[i] = left;
+    left *= a[i];
   }
-  let cur = 1;
-  for (let i = a.length - 1; i >= 0; i--) {
-    res[i] = pre[i] * cur;
-    cur *= a[i];
+  for (let i = n - 1, right = 1; i >= 0; --i) {
+    output[i] *= right;
+    right *= a[i];
   }
-  return res;
+  return output;
 };

lcof/面试题66. 构建乘积数组/Solution.py

@@ -1,13 +1,12 @@
 class Solution:
     def constructArr(self, a: List[int]) -> List[int]:
-        if not a:
-            return []
-        dp1 = [1 for i in a]
-        dp2 = [1 for i in a]
         n = len(a)
-        dp1[0], dp2[n - 1] = a[0], a[n - 1]
-        for i in range(1, n):
-            dp1[i] = dp1[i - 1] * a[i]
-        for i in range(n - 2, -1, -1):
-            dp2[i] = dp2[i + 1] * a[i]
-        return [(1 if i - 1 < 0 else dp1[i - 1]) * (1 if i + 1 >= n else dp2[i + 1]) for i in range(0, n)]
+        output = [1 for _ in a]
+        left = right = 1
+        for i in range(n):
+            output[i] = left
+            left *= a[i]
+        for i in range(n - 1, -1, -1):
+            output[i] *= right
+            right *= a[i]
+        return output

solution/0200-0299/0238.Product of Array Except Self/README.md

@@ -34,15 +34,62 @@
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
-
+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        n = len(nums)
+        output = [1 for _ in nums]
+        left = right = 1
+        for i in range(n):
+            output[i] = left
+            left *= nums[i]
+        for i in range(n - 1, -1, -1):
+            output[i] *= right
+            right *= nums[i]
+        return output
 ```
 
 ### **Java**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```java
+class Solution {
+    public int[] productExceptSelf(int[] nums) {
+        int n = nums.length;
+        int[] output = new int[n];
+        for (int i = 0, left = 1; i < n; ++i) {
+            output[i] = left;
+            left *= nums[i];
+        }
+        for (int i = n - 1, right = 1; i >= 0; --i) {
+            output[i] *= right;
+            right *= nums[i];
+        }
+        return output;
+    }
+}
+```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var productExceptSelf = function (nums) {
+  const n = nums.length;
+  let output = new Array(n);
+  for (let i = 0, left = 1; i < n; ++i) {
+    output[i] = left;
+    left *= nums[i];
+  }
+  for (let i = n - 1, right = 1; i >= 0; --i) {
+    output[i] *= right;
+    right *= nums[i];
+  }
+  return output;
+};
 ```
 
 ### **...**

solution/0200-0299/0238.Product of Array Except Self/README_EN.md

@@ -27,13 +27,60 @@ Could you solve it with constant space complexity? (The output array <strong>doe
 ### **Python3**
 
 ```python
-
+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        n = len(nums)
+        output = [1 for _ in nums]
+        left = right = 1
+        for i in range(n):
+            output[i] = left
+            left *= nums[i]
+        for i in range(n - 1, -1, -1):
+            output[i] *= right
+            right *= nums[i]
+        return output
 ```
 
 ### **Java**
 
 ```java
+class Solution {
+    public int[] productExceptSelf(int[] nums) {
+        int n = nums.length;
+        int[] output = new int[n];
+        for (int i = 0, left = 1; i < n; ++i) {
+            output[i] = left;
+            left *= nums[i];
+        }
+        for (int i = n - 1, right = 1; i >= 0; --i) {
+            output[i] *= right;
+            right *= nums[i];
+        }
+        return output;
+    }
+}
+```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var productExceptSelf = function (nums) {
+  const n = nums.length;
+  let output = new Array(n);
+  for (let i = 0, left = 1; i < n; ++i) {
+    output[i] = left;
+    left *= nums[i];
+  }
+  for (let i = n - 1, right = 1; i >= 0; --i) {
+    output[i] *= right;
+    right *= nums[i];
+  }
+  return output;
+};
 ```
 
 ### **...**

solution/0200-0299/0238.Product of Array Except Self/Solution.java

@@ -1,14 +1,14 @@
 class Solution {
     public int[] productExceptSelf(int[] nums) {
-        int len = nums.length;
-        int[] output = new int[len];
-        for (int i = 0, left = 1; i < len; i++) {
+        int n = nums.length;
+        int[] output = new int[n];
+        for (int i = 0, left = 1; i < n; ++i) {
             output[i] = left;
             left *= nums[i];
         }
-        for (int j = len - 1, right = 1; j >= 0; j--) {
-            output[j] *= right;
-            right *= nums[j];
+        for (int i = n - 1, right = 1; i >= 0; --i) {
+            output[i] *= right;
+            right *= nums[i];
         }
         return output;
     }

solution/0200-0299/0238.Product of Array Except Self/Solution.js

@@ -0,0 +1,17 @@
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var productExceptSelf = function (nums) {
+  const n = nums.length;
+  let output = new Array(n);
+  for (let i = 0, left = 1; i < n; ++i) {
+    output[i] = left;
+    left *= nums[i];
+  }
+  for (let i = n - 1, right = 1; i >= 0; --i) {
+    output[i] *= right;
+    right *= nums[i];
+  }
+  return output;
+};

solution/0200-0299/0238.Product of Array Except Self/Solution.py

@@ -0,0 +1,12 @@
+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        n = len(nums)
+        output = [1 for _ in nums]
+        left = right = 1
+        for i in range(n):
+            output[i] = left
+            left *= nums[i]
+        for i in range(n - 1, -1, -1):
+            output[i] *= right
+            right *= nums[i]
+        return output