Maximum profit from sale of wines

• Difficulty Level : Medium
• Last Updated : 27 May, 2021

Given n wines in a row, with integers denoting the cost of each wine respectively. Each year you can sale the first or the last wine in the row. However, the price of wines increases over time. Let the initial profits from the wines be P1, P2, P3…Pn. On the Yth year, the profit from the ith wine will be Y*Pi. For each year, your task is to print “beg” or “end” denoting whether first or last wine should be sold. Also, calculate the maximum profit from all the wines.
Examples :

Input: Price of wines: 2 4 6 2 5
Output: beg end end beg beg
64
Explanation :

Approach : It is a standard Dynamic Programming problem. It initially looks like a greedy problem in which we should sell the cheaper of the wines each year but the example case (year 2) clearly proves the approach is wrong. Sometimes we need to sell an expensive wine earlier to save relatively costly wines for later years (Here, if 4 was sold in the 2nd year, in the 4th year we had to sell 2 which would be waste of a heavy coefficient).
The second problem is to “store the strategy” to obtain the calculated price which has a fairly standard method that can be used in other problems as well. The idea is to store the optimal action for each state and use that to navigate through the optimal states starting from the initial state.

C++

 // Program to calculate maximum price of wines#include using namespace std; #define N 1000 int dp[N][N]; // This array stores the "optimal action"// for each state i, jint sell[N][N]; // Function to maximize profitint maxProfitUtil(int price[], int begin,                  int end, int n) {    if (dp[begin][end] != -1)        return dp[begin][end];     int year = n - (end - begin);     if (begin == end)        return year * price[begin];        // x = maximum profit on selling the    // wine from the front this year    int x = price[begin] * year +            maxProfitUtil(price, begin + 1, end, n);     // y = maximum profit on selling the    // wine from the end this year    int y = price[end] * year +            maxProfitUtil(price, begin, end - 1, n);     int ans = max(x, y);    dp[begin][end] = ans;     if (x >= y)        sell[begin][end] = 0;    else        sell[begin][end] = 1;     return ans;} // Util Function to calculate maxProfitint maxProfit(int price[], int n) {    // reseting the dp table    for (int i = 0; i < N; i++)        for (int j = 0; j < N; j++)            dp[i][j] = -1;     int ans = maxProfitUtil(price, 0, n - 1, n);     int i = 0, j = n - 1;     while (i <= j) {        // sell[i][j]=0 implies selling the        // wine from beginning will be more        // profitable in the long run        if (sell[i][j] == 0) {            cout << "beg ";            i++;        }  else {            cout << "end ";            j--;        }    }     cout << endl;     return ans;} // Driver codeint main() {    // Price array    int price[] = { 2, 4, 6, 2, 5 };     int n = sizeof(price) / sizeof(price[0]);     int ans = maxProfit(price, n);     cout << ans << endl;     return 0;}

Java

 // Program to calculate maximum price of winesimport java.io.*; class GFG {         static int N = 1000;         static int [][]dp = new int[N][N];         // This array stores the "optimal action"    // for each state i, j    static int [][]sell = new int[N][N];         // Function to maximize profit    static int maxProfitUtil(int price[],                   int begin, int end, int n)    {        if (dp[begin][end] != -1)            return dp[begin][end];             int year = n - (end - begin);             if (begin == end)            return year * price[begin];             // x = maximum profit on selling the        // wine from the front this year        int x = price[begin] * year +                maxProfitUtil(price, begin + 1,                                       end, n);             // y = maximum profit on selling the        // wine from the end this year        int y = price[end] * year +                maxProfitUtil(price, begin,                                  end - 1, n);             int ans = Math.max(x, y);        dp[begin][end] = ans;             if (x >= y)            sell[begin][end] = 0;        else            sell[begin][end] = 1;             return ans;    }         // Util Function to calculate maxProfit    static int maxProfit(int price[], int n)    {                 // reseting the dp table        for (int i = 0; i < N; i++)            for (int j = 0; j < N; j++)                dp[i][j] = -1;             int ans = maxProfitUtil(price, 0,                                  n - 1, n);             int i = 0, j = n - 1;             while (i <= j) {                 // sell[i][j]=0 implies selling            // the wine from beginning will            // be more profitable in the            // long run            if(sell[i][j] == 0){                System.out.print( "beg ");                i++;            }            else            {                System.out.print( "end ");                j--;            }        }             System.out.println();             return ans;    }         // Driver code    public static void main (String[] args)    {        // Price array        int price[] = { 2, 4, 6, 2, 5 };             int n = price.length;             int ans = maxProfit(price, n);             System.out.println( ans );    }} // This code is contributed by anuj_67.

Python3

 # Python3 Program to calculate# maximum price of winesN = 1000dp = [ [-1 for col in range(N)]               for row in range(N)] # This array stores the "optimal action"# for each state i, jsell = [ [0 for col in range(N)]            for row in range(N)] # Function to maximize profitdef maxProfitUtil(price, begin, end, n):         if (dp[begin][end] != -1):        return dp[begin][end]     year = n - (end - begin)     if (begin == end):        return year * price[begin]     # x = maximum profit on selling the    # wine from the front this year    x = price[begin] * year + \        maxProfitUtil(price, begin + 1, end, n)     # y = maximum profit on selling the    # wine from the end this year    y = price[end] * year + \        maxProfitUtil(price, begin, end - 1, n)     ans = max(x, y)    dp[begin][end] = ans     if (x >= y):        sell[begin][end] = 0    else:        sell[begin][end] = 1     return ans # Util Function to calculate maxProfitdef maxProfit(price, n):     ans = maxProfitUtil(price, 0, n - 1, n)     i = 0    j = n - 1     while (i <= j):                 # sell[i][j]=0 implies selling the        # wine from beginning will be more        # profitable in the long run        if (sell[i][j] == 0):            print("beg", end = " ")            i = i + 1        else:            print("end", end = " ")            j = j - 1         print(" ")    return ans # Driver code # Price arrayprice = [ 2, 4, 6, 2, 5 ] size = 5 ans = maxProfit(price, size); print(ans) # This code is contributed by ashutosh450

C#

 // C# Program to calculate maximum// price of winesusing System;class GFG {         static int N = 1000;    static int [,]dp = new int[N, N];         // This array stores the "optimal action"    // for each state i, j    static int [,]sell = new int[N,N];         // Function to maximize profit    static int maxProfitUtil(int []price,               int begin, int end, int n)    {        if (dp[begin,end] != -1)            return dp[begin,end];             int year = n - (end - begin);             if (begin == end)            return year * price[begin];             // x = maximum profit on selling the        // wine from the front this year        int x = price[begin] * year +                maxProfitUtil(price, begin + 1,                                       end, n);             // y = maximum profit on selling the        // wine from the end this year        int y = price[end] * year +                maxProfitUtil(price, begin,                                end - 1, n);             int ans = Math.Max(x, y);        dp[begin,end] = ans;             if (x >= y)            sell[begin,end] = 0;        else            sell[begin,end] = 1;             return ans;    }         // Util Function to calculate maxProfit    static int maxProfit(int []price, int n)    {        int i, j;                  // reseting the dp table        for(i = 0; i < N; i++)            for(j = 0; j < N; j++)                dp[i, j] = -1;             int ans = maxProfitUtil(price, 0,                                n - 1, n);             i = 0; j = n - 1;             while (i <= j) {                 // sell[i][j]=0 implies selling            // the wine from beginning will            // be more profitable in the            // long run            if(sell[i, j] == 0){                Console.Write( "beg ");                i++;            }            else            {                Console.Write( "end ");                j--;            }        }         Console.WriteLine();             return ans;    }         // Driver Code    public static void Main ()    {         // Price array        int []price = {2, 4, 6, 2, 5};        int n = price.Length;        int ans = maxProfit(price, n);        Console.WriteLine( ans );    }} // This code is contributed by anuj_67.

Javascript



Output:

beg end end beg beg
64

Time Complexity: O(n2)

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