day35

买卖股票最佳时机IV
class Solution {
public:
int maxProfit(int k, vector& prices) {
vector<vector> dp(prices.size(), vector(2k, 0));
for(int i = 0; i < 2k; i++)
{
if(i % 2 == 0)
{
dp[0][i] = -prices[0];
}
}
for(int i = 1; i < prices.size(); ++i)
{
dp[i][0] = max(dp[i-1][0], -prices[i]);
for(int j = 1; j < 2*k; ++j)
{
if(j % 2 == 0)
{
dp[i][j] = max(dp[i-1][j], dp[i-1][j-1]-prices[i]);
}
else
{
dp[i][j] = max(dp[i-1][j], dp[i-1][j-1]+prices[i]);
}
}

    }
    return dp[prices.size()-1][2*k-1];
}

};

买卖股票的最佳时机冷冻期
class Solution {
public:
int maxProfit(vector& prices) {
vector<vector> dp(prices.size(), vector(4, 0));
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][1]-prices[i], dp[i-1][3]-prices[i]));
dp[i][1] = max(dp[i-1][1], dp[i-1][3]);
dp[i][2] = dp[i][0]+prices[i];
dp[i][3] = dp[i-1][2];
}
return max(dp[prices.size()-1][1], max(dp[prices.size()-1][2], dp[prices.size()-1][3]));
}
};

买卖股票最佳时机含手续费

class Solution {
public:
int maxProfit(vector& prices, int fee) {
vector<vector> dp(prices.size(), vector(2,0));
dp[0][0] = -prices[0];
dp[0][1] = 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];
}
};