diff --git a/Solution/714. Best Time to Buy and Sell Stock with Transaction Fee/714. Best Time to Buy and Sell Stock with Transaction Fee.py b/Solution/714. Best Time to Buy and Sell Stock with Transaction Fee/714. Best Time to Buy and Sell Stock with Transaction Fee.py
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+class Solution:
+ def maxProfit(self, prices: List[int], fee: int) -> int:
+ @cache
+ def dfs(i: int, j: int) -> int:
+ if i >= len(prices):
+ return 0
+ ans = dfs(i + 1, j)
+ if j:
+ ans = max(ans, prices[i] + dfs(i + 1, 0) - fee)
+ else:
+ ans = max(ans, -prices[i] + dfs(i + 1, 1))
+ return ans
+
+ return dfs(0, 0)
\ No newline at end of file
diff --git a/Solution/714. Best Time to Buy and Sell Stock with Transaction Fee/readme.md b/Solution/714. Best Time to Buy and Sell Stock with Transaction Fee/readme.md
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+
+
+
+# [714. Best Time to Buy and Sell Stock with Transaction Fee](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee)
+
+---
+- **comments**: true
+- **difficulty**: Medium
+- **tags**:
+ - Greedy
+ - Array
+ - Dynamic Programming
+---
+
+## Description
+
+
+
+
You are given an array prices where prices[i] is the price of a given stock on the ith day, and an integer fee representing a transaction fee.
+
+Find the maximum profit you can achieve. You may complete as many transactions as you like, but you need to pay the transaction fee for each transaction.
+
+Note:
+
+
+ - You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).
+ - The transaction fee is only charged once for each stock purchase and sale.
+
+
+
+Example 1:
+
+
+Input: prices = [1,3,2,8,4,9], fee = 2
+Output: 8
+Explanation: The maximum profit can be achieved by:
+- Buying at prices[0] = 1
+- Selling at prices[3] = 8
+- Buying at prices[4] = 4
+- Selling at prices[5] = 9
+The total profit is ((8 - 1) - 2) + ((9 - 4) - 2) = 8.
+
+
+Example 2:
+
+
+Input: prices = [1,3,7,5,10,3], fee = 3
+Output: 6
+
+
+
+Constraints:
+
+
+ 1 <= prices.length <= 5 * 104
+ 1 <= prices[i] < 5 * 104
+ 0 <= fee < 5 * 104
+
+
+
+
+## Solutions
+
+
+
+### Solution 1: Memoization
+
+We design a function $dfs(i, j)$, which represents the maximum profit that can be obtained starting from day $i$ with state $j$. Here, $j$ can take the values $0$ and $1$, representing not holding and holding a stock, respectively. The answer is $dfs(0, 0)$.
+
+The execution logic of the function $dfs(i, j)$ is as follows:
+
+If $i \geq n$, there are no more stocks to trade, so we return $0$.
+
+Otherwise, we can choose not to trade, in which case $dfs(i, j) = dfs(i + 1, j)$. We can also choose to trade stocks. If $j \gt 0$, it means that we currently hold a stock and can sell it. In this case, $dfs(i, j) = prices[i] + dfs(i + 1, 0) - fee$. If $j = 0$, it means that we currently do not hold a stock and can buy one. In this case, $dfs(i, j) = -prices[i] + dfs(i + 1, 1)$. We take the maximum value as the return value of the function $dfs(i, j)$.
+
+The answer is $dfs(0, 0)$.
+
+To avoid redundant calculations, we use memoization to record the return value of $dfs(i, j)$ in an array $f$. If $f[i][j]$ is not equal to $-1$, it means that we have already calculated it, so we can directly return $f[i][j]$.
+
+The time complexity is $O(n)$, and the space complexity is $O(n)$. Here, $n$ is the length of the array $prices$.
+
+
+
+#### Python3
+
+```python
+class Solution:
+ def maxProfit(self, prices: List[int], fee: int) -> int:
+ @cache
+ def dfs(i: int, j: int) -> int:
+ if i >= len(prices):
+ return 0
+ ans = dfs(i + 1, j)
+ if j:
+ ans = max(ans, prices[i] + dfs(i + 1, 0) - fee)
+ else:
+ ans = max(ans, -prices[i] + dfs(i + 1, 1))
+ return ans
+
+ return dfs(0, 0)
+```
+
+#### Java
+
+```java
+class Solution {
+ private Integer[][] f;
+ private int[] prices;
+ private int fee;
+
+ public int maxProfit(int[] prices, int fee) {
+ f = new Integer[prices.length][2];
+ this.prices = prices;
+ this.fee = fee;
+ return dfs(0, 0);
+ }
+
+ private int dfs(int i, int j) {
+ if (i >= prices.length) {
+ return 0;
+ }
+ if (f[i][j] != null) {
+ return f[i][j];
+ }
+ int ans = dfs(i + 1, j);
+ if (j > 0) {
+ ans = Math.max(ans, prices[i] + dfs(i + 1, 0) - fee);
+ } else {
+ ans = Math.max(ans, -prices[i] + dfs(i + 1, 1));
+ }
+ return f[i][j] = ans;
+ }
+}
+```
+
+#### C++
+
+```cpp
+class Solution {
+public:
+ int maxProfit(vector& prices, int fee) {
+ int n = prices.size();
+ int f[n][2];
+ memset(f, -1, sizeof(f));
+ function dfs = [&](int i, int j) {
+ if (i >= prices.size()) {
+ return 0;
+ }
+ if (f[i][j] != -1) {
+ return f[i][j];
+ }
+ int ans = dfs(i + 1, j);
+ if (j) {
+ ans = max(ans, prices[i] + dfs(i + 1, 0) - fee);
+ } else {
+ ans = max(ans, -prices[i] + dfs(i + 1, 1));
+ }
+ return f[i][j] = ans;
+ };
+ return dfs(0, 0);
+ }
+};
+```
+
+#### Go
+
+```go
+func maxProfit(prices []int, fee int) int {
+ n := len(prices)
+ f := make([][2]int, n)
+ for i := range f {
+ f[i] = [2]int{-1, -1}
+ }
+ var dfs func(i, j int) int
+ dfs = func(i, j int) int {
+ if i >= n {
+ return 0
+ }
+ if f[i][j] != -1 {
+ return f[i][j]
+ }
+ ans := dfs(i+1, j)
+ if j > 0 {
+ ans = max(ans, prices[i]+dfs(i+1, 0)-fee)
+ } else {
+ ans = max(ans, -prices[i]+dfs(i+1, 1))
+ }
+ f[i][j] = ans
+ return ans
+ }
+ return dfs(0, 0)
+}
+```
+
+#### TypeScript
+
+```ts
+function maxProfit(prices: number[], fee: number): number {
+ const n = prices.length;
+ const f: number[][] = Array.from({ length: n }, () => [-1, -1]);
+ const dfs = (i: number, j: number): number => {
+ if (i >= n) {
+ return 0;
+ }
+ if (f[i][j] !== -1) {
+ return f[i][j];
+ }
+ let ans = dfs(i + 1, j);
+ if (j) {
+ ans = Math.max(ans, prices[i] + dfs(i + 1, 0) - fee);
+ } else {
+ ans = Math.max(ans, -prices[i] + dfs(i + 1, 1));
+ }
+ return (f[i][j] = ans);
+ };
+ return dfs(0, 0);
+}
+```
+
+
+
+
+
+
+
+### Solution 2: Dynamic Programming
+
+We define $f[i][j]$ as the maximum profit that can be obtained up to day $i$ with state $j$. Here, $j$ can take the values $0$ and $1$, representing not holding and holding a stock, respectively. We initialize $f[0][0] = 0$ and $f[0][1] = -prices[0]$.
+
+When $i \geq 1$, if we do not hold a stock at the current day, then $f[i][0]$ can be obtained by transitioning from $f[i - 1][0]$ and $f[i - 1][1] + prices[i] - fee$, i.e., $f[i][0] = \max(f[i - 1][0], f[i - 1][1] + prices[i] - fee)$. If we hold a stock at the current day, then $f[i][1]$ can be obtained by transitioning from $f[i - 1][1]$ and $f[i - 1][0] - prices[i]$, i.e., $f[i][1] = \max(f[i - 1][1], f[i - 1][0] - prices[i])$. The final answer is $f[n - 1][0]$.
+
+The time complexity is $O(n)$, and the space complexity is $O(n)$. Here, $n$ is the length of the array $prices$.
+
+We notice that the transition of the state $f[i][]$ only depends on $f[i - 1][]$ and $f[i - 2][]$. Therefore, we can use two variables $f_0$ and $f_1$ to replace the array $f$, reducing the space complexity to $O(1)$.
+
+
+
+#### Python3
+
+```python
+class Solution:
+ def maxProfit(self, prices: List[int], fee: int) -> int:
+ n = len(prices)
+ f = [[0] * 2 for _ in range(n)]
+ f[0][1] = -prices[0]
+ for i in range(1, n):
+ f[i][0] = max(f[i - 1][0], f[i - 1][1] + prices[i] - fee)
+ f[i][1] = max(f[i - 1][1], f[i - 1][0] - prices[i])
+ return f[n - 1][0]
+```
+
+#### Java
+
+```java
+class Solution {
+ public int maxProfit(int[] prices, int fee) {
+ int n = prices.length;
+ int[][] f = new int[n][2];
+ f[0][1] = -prices[0];
+ for (int i = 1; i < n; ++i) {
+ f[i][0] = Math.max(f[i - 1][0], f[i - 1][1] + prices[i] - fee);
+ f[i][1] = Math.max(f[i - 1][1], f[i - 1][0] - prices[i]);
+ }
+ return f[n - 1][0];
+ }
+}
+```
+
+#### C++
+
+```cpp
+class Solution {
+public:
+ int maxProfit(vector& prices, int fee) {
+ int n = prices.size();
+ int f[n][2];
+ memset(f, 0, sizeof(f));
+ f[0][1] = -prices[0];
+ for (int i = 1; i < n; ++i) {
+ f[i][0] = max(f[i - 1][0], f[i - 1][1] + prices[i] - fee);
+ f[i][1] = max(f[i - 1][1], f[i - 1][0] - prices[i]);
+ }
+ return f[n - 1][0];
+ }
+};
+```
+
+#### Go
+
+```go
+func maxProfit(prices []int, fee int) int {
+ n := len(prices)
+ f := make([][2]int, n)
+ f[0][1] = -prices[0]
+ for i := 1; i < n; i++ {
+ f[i][0] = max(f[i-1][0], f[i-1][1]+prices[i]-fee)
+ f[i][1] = max(f[i-1][1], f[i-1][0]-prices[i])
+ }
+ return f[n-1][0]
+}
+```
+
+#### TypeScript
+
+```ts
+function maxProfit(prices: number[], fee: number): number {
+ const n = prices.length;
+ const f: number[][] = Array.from({ length: n }, () => [0, 0]);
+ f[0][1] = -prices[0];
+ for (let i = 1; i < n; ++i) {
+ f[i][0] = Math.max(f[i - 1][0], f[i - 1][1] + prices[i] - fee);
+ f[i][1] = Math.max(f[i - 1][1], f[i - 1][0] - prices[i]);
+ }
+ return f[n - 1][0];
+}
+```
+
+
+
+
+
+
+
+### Solution 3
+
+
+
+#### Python3
+
+```python
+class Solution:
+ def maxProfit(self, prices: List[int], fee: int) -> int:
+ f0, f1 = 0, -prices[0]
+ for x in prices[1:]:
+ f0, f1 = max(f0, f1 + x - fee), max(f1, f0 - x)
+ return f0
+```
+
+#### Java
+
+```java
+class Solution {
+ public int maxProfit(int[] prices, int fee) {
+ int f0 = 0, f1 = -prices[0];
+ for (int i = 1; i < prices.length; ++i) {
+ int g0 = Math.max(f0, f1 + prices[i] - fee);
+ f1 = Math.max(f1, f0 - prices[i]);
+ f0 = g0;
+ }
+ return f0;
+ }
+}
+```
+
+#### C++
+
+```cpp
+class Solution {
+public:
+ int maxProfit(vector& prices, int fee) {
+ int f0 = 0, f1 = -prices[0];
+ for (int i = 1; i < prices.size(); ++i) {
+ int g0 = max(f0, f1 + prices[i] - fee);
+ f1 = max(f1, f0 - prices[i]);
+ f0 = g0;
+ }
+ return f0;
+ }
+};
+```
+
+#### Go
+
+```go
+func maxProfit(prices []int, fee int) int {
+ f0, f1 := 0, -prices[0]
+ for _, x := range prices[1:] {
+ f0, f1 = max(f0, f1+x-fee), max(f1, f0-x)
+ }
+ return f0
+}
+```
+
+#### TypeScript
+
+```ts
+function maxProfit(prices: number[], fee: number): number {
+ const n = prices.length;
+ let [f0, f1] = [0, -prices[0]];
+ for (const x of prices.slice(1)) {
+ [f0, f1] = [Math.max(f0, f1 + x - fee), Math.max(f1, f0 - x)];
+ }
+ return f0;
+}
+```
+
+
+
+
+
+
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