Optimal Game Strategy - Wrong Answer

#1

Please help me find the mistake.

#2

your approach is greedy
consider
4 6 2 3 1
according to this a picks 4 first but then b picks 6 a picks 2 b picks 3
b wins
however you should use try both substrates and get the answer for which coin should be picked
int q1 = a[i] + recursivefun(a, i+1, n) n=last index, i = first index
int q2 = a[n] + recursivefun(a, i, n-1)
ans = max(q1, q2)
return ans

#3

So, I tried changed the code aptly but it still doesn’t seem to work.
How do I include 2 players?

#4


see what the second player wants it to return minimum of the leftover game so he returns the minimum

#5

Works fine, but I am getting TLE in once case.
Please help resolve that too.

#6

you have to use the concept of DP for that
way 1 is memoisation store the result for ever i and n in a 2d matrix and if that substrate is already computed return it
way 2 is a 2d dp formulae
for (int gap = 0; gap < n; ++gap) {
for (int i = 0, j = gap; j < n; ++i, ++j) {

        // Here x is value of F(i+2, j), y is F(i+1, j-1) and 
        // z is F(i, j-2) in above recursive formula 
        int x = ((i + 2) <= j) ? table[i + 2][j] : 0; 
        int y = ((i + 1) <= (j - 1)) ? table[i + 1][j - 1] : 0; 
        int z = (i <= (j - 2)) ? table[i][j - 2] : 0; 

        table[i][j] = max(arr[i] + min(x, y), arr[j] + min(y, z)); 
    }
#7

hey @abhishekchoudhary if your doubt is solved, please mark it as resolved

#8

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