Create 309-Best-Time-To-Buy-And-Sell-Stock-With-Cooldown.js

Author: Ahmad-A0

javascript/309-Best-Time-To-Buy-And-Sell-Stock-With-Cooldown.js

@@ -0,0 +1,26 @@
+/**
+ * @param {number[]} prices
+ * @return {number}
+ */
+var maxProfit = function(prices) {
+    let dp = {} // key=[i, buying] val=max_profit
+    
+    const dfs = (i, buying) => {
+        if (i >= prices.length) return 0
+        if (dp[[i, buying]]) return dp[[i, buying]]
+        
+        const cooldown = dfs(i + 1, buying)
+        if (buying) {
+            const buy = dfs(i + 1, !buying) - prices[i]
+            dp[[i, buying]] = Math.max(buy, cooldown)
+        }
+        else {
+            sell = dfs(i + 2, !buying) + prices[i]
+            dp[[i, buying]] = Math.max(sell, cooldown)
+        }
+        return dp[[i, buying]]
+    }
+    
+    return dfs(0, true)
+};
+