https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3287/\n\nI just wrote a DP solution in python but it gets TLE. I know simpler O(N) solution but I was just hoping to try a DP solution.\n\nThe following code also has a complexity O(N) as I\'m memoizing values and don\'t calculate repeated values, can anyone suggest why I may be getting TLE?\n\n```\nclass Solution:\n    import sys\n    sys.setrecursionlimit(60000)\n    def rec(self, i):\n        if i >= len(self.memo):\n            return 0\n        if self.memo[i] != -1:\n            return self.memo[i]\n        \n        # I\'m buying on ith day\n        c1 = self.prices[i]\n        c2 = 0\n        for j in range(i+1,len(self.prices)):\n            # lets say I\'m seliing on jth day\n            c2 = max(c2, (self.prices[j]-c1) + self.rec(j+1))\n            \n        # I\'m not buying on ith day\n        \n        c2 = max(c2, self.rec(i+1)) # just go to next day\n        \n        self.memo[i] = c2\n            \n        return c2\n        \n    def maxProfit(self, prices):\n        self.prices = prices\n        self.memo = [-1]*len(prices)\n        \n        ans = self.rec(0)\n        \n        return ans\n\n```

https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3287/\n\nI just wrote a DP solution in python but it gets TLE. I know simpler