DP

股票交易两类题型
日不会做

Author: h2pl

src/DP/其他问题如股票/需要冷却期的股票交易.java

@@ -0,0 +1,41 @@
+package DP.其他问题如股票;
+
+/**
+ * Created by 周杰伦 on 2018/4/9.
+ */
+public class 需要冷却期的股票交易 {
+    public int maxProfit(int[] prices) {
+        if (prices.length < 2)return 0;
+        if (prices.length == 2)return prices[1] - prices[0];
+        if (prices.length == 3) {
+            int max = prices[1] - prices[0];
+            max = Math.max(prices[2] - prices[1], max);
+            max = Math.max(prices[2] - prices[0], max);
+            return max;
+        }
+        //buy at i price and sell at j price and cooldown at j + 1
+        int [][]dp = new int[prices.length][prices.length];
+
+        dp[0][1] = prices[1] - prices[0];
+        for (int i = 0;i < prices.length;i ++) {
+            for (int j = i + 1;j < prices.length;j ++) {
+                if (i >= 3) {
+                    dp[i][j] = Math.max(prices[j] - prices[i - 3],
+                            dp[i - 3][j - 3] + prices[j] - prices[i]);
+                }else {
+                    dp[i][j] = dp[0][1];
+                }
+            }
+        }
+        for (int i = 4;i < prices.length;i ++) {
+            dp[0][i] = Math.max(prices[i] - prices[0], dp[0][1] + dp[3][i]);
+        }
+        int max = 0;
+        for (int i = 0;i < dp.length;i ++) {
+            for (int j = i + 1;j < dp.length;j ++) {
+
+            }
+        }
+        return max;
+    }
+}