188. 买卖股票的最佳时机 IV
class Solution {
public:int maxProfit(int k, vector<int>& prices) {if (prices.size() == 0) return 0;vector<vector<int>> dp(prices.size(), vector<int>(2 * k + 1, 0));for (int i = 1; i < 2 * k + 1; i += 2) {dp[0][i] = -prices[0];}for (int i = 1; i < prices.size(); i++) {for (int j = 1; j < 2 * k; j += 2) {dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - 1] - prices[i]);dp[i][j + 1] = max(dp[i - 1][j + 1], dp[i - 1][j] + prices[i]);}}return dp[prices.size() - 1][2 * k];}
};
309. 买卖股票的最佳时机含冷冻期
2种状态
class Solution {
public:int maxProfit(vector<int>& prices) {if (prices.size() == 1) return 0;vector<vector<int>> dp(prices.size(), vector<int>(2, 0)); //1 持有 0 不持有dp[0][1] = -prices[0];dp[1][0] = max(dp[0][0], dp[0][1] + prices[1]);dp[1][1] = max(dp[0][0] - prices[1], dp[0][1]);for (int i = 2; i < prices.size(); i++) {dp[i][0] = max(dp[i - 1][0], dp[i - 1][1] + prices[i]);dp[i][1] = max(dp[i - 1][1], dp[i - 2][0] - prices[i]);}return max(dp[prices.size() - 1][0], dp[prices.size() - 1][1]);}
};
4种状态
dp[0][0] = -prices[0];for (int i = 1; i < prices.size(); i++) {dp[i][0] = max(dp[i - 1][0], max(dp[i - 1][3] - prices[i], dp[i - 1][1] - prices[i]));dp[i][1] = max(dp[i - 1][1], dp[i - 1][3]);dp[i][2] = dp[i - 1][0] + prices[i]; dp[i][3] = dp[i - 1][2];}return max(dp[n - 1][3], max(dp[n - 1][1], dp[n - 1][2]));
714. 买卖股票的最佳时机含手续费
class Solution {
public:int maxProfit(vector<int>& prices, int fee) {vector<vector<int>> dp(prices.size(), vector<int>(2, 0)); //0持有 1不持有dp[0][0] = -prices[0];for (int i = 1; i < prices.size(); i++) {dp[i][0] = max(dp[i - 1][0], dp[i - 1][1] - prices[i]);dp[i][1] = max(dp[i - 1][1], dp[i - 1][0] + prices[i] - fee);}return dp[prices.size() - 1][1];}
};