|
| 1 | +// A simple C++ program to find |
| 2 | +// maximum score that |
| 3 | +// maximizing player can get. |
| 4 | +#include<bits/stdc++.h> |
| 5 | +using namespace std; |
| 6 | + |
| 7 | +// Returns the optimal value a maximizer can obtain. |
| 8 | +// depth is current depth in game tree. |
| 9 | +// nodeIndex is index of current node in scores[]. |
| 10 | +// isMax is true if current move is |
| 11 | +// of maximizer, else false |
| 12 | +// scores[] stores leaves of Game tree. |
| 13 | +// h is maximum height of Game tree |
| 14 | +int minimax(int depth, int nodeIndex, bool isMax, |
| 15 | + int scores[], int h) |
| 16 | +{ |
| 17 | + // Terminating condition. i.e |
| 18 | + // leaf node is reached |
| 19 | + if (depth == h) |
| 20 | + return scores[nodeIndex]; |
| 21 | + |
| 22 | + // If current move is maximizer, |
| 23 | + // find the maximum attainable |
| 24 | + // value |
| 25 | + if (isMax) |
| 26 | + return max(minimax(depth+1, nodeIndex*2, false, scores, h), |
| 27 | + minimax(depth+1, nodeIndex*2 + 1, false, scores, h)); |
| 28 | + |
| 29 | + // Else (If current move is Minimizer), find the minimum |
| 30 | + // attainable value |
| 31 | + else |
| 32 | + return min(minimax(depth+1, nodeIndex*2, true, scores, h), |
| 33 | + minimax(depth+1, nodeIndex*2 + 1, true, scores, h)); |
| 34 | +} |
| 35 | + |
| 36 | +// A utility function to find Log n in base 2 |
| 37 | +int log2(int n) |
| 38 | +{ |
| 39 | +return (n==1)? 0 : 1 + log2(n/2); |
| 40 | +} |
| 41 | + |
| 42 | +// Driver code |
| 43 | +int main() |
| 44 | +{ |
| 45 | + // The number of elements in scores must be |
| 46 | + // a power of 2. |
| 47 | + int scores[] = {3, 5, 2, 9, 12, 5, 23, 23}; |
| 48 | + int n = sizeof(scores)/sizeof(scores[0]); |
| 49 | + int h = log2(n); |
| 50 | + int res = minimax(0, 0, true, scores, h); |
| 51 | + cout << "The optimal value is : " << res << endl; |
| 52 | + return 0; |
| 53 | +} |
0 commit comments