Implement solution for "Best Time to Buy and Sell Stock IV"

Author: kaif969

188. Best Time to Buy and Sell Stock IV.cpp

@@ -0,0 +1,27 @@
+class Solution {
+public:
+    vector<vector<vector<int>>> dp;
+
+    int profit(vector<int>& prices, int i, int isBuy, int k) {
+        if (i == prices.size() || k == 0) return 0;
+
+        if (dp[i][isBuy][k] != -1) return dp[i][isBuy][k];
+
+        int a, b;
+        if (isBuy) {
+            a = profit(prices, i + 1, 1, k);
+            b = profit(prices, i + 1, 0, k) - prices[i];
+        } else {
+            a = profit(prices, i + 1, 0, k);
+            b = profit(prices, i + 1, 1, k - 1) + prices[i];
+        }
+
+        return dp[i][isBuy][k] = max(a, b);
+    }
+
+    int maxProfit(int k, vector<int>& prices) {
+        int n = prices.size();
+        dp = vector<vector<vector<int>>>(n, vector<vector<int>>(2, vector<int>(k + 1, -1)));
+        return profit(prices, 0, 1, k);
+    }
+};