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Diffstat (limited to 'knight_probability_chessboard.cpp')
-rw-r--r-- | knight_probability_chessboard.cpp | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/knight_probability_chessboard.cpp b/knight_probability_chessboard.cpp deleted file mode 100644 index 0c5094d..0000000 --- a/knight_probability_chessboard.cpp +++ /dev/null @@ -1,41 +0,0 @@ -// 688. Knight Probability in Chessboard -#include "leetcode.h" - -/* - * on an 'n x n' chessboard, a knight starts at the cell '(row, column)' and - * attempts to make exactly 'k' moves. the rows and columns are 0-indexed, so - * the top-left cell is '(0, 0)', and the bottom-right cell is '(n - 1, n - 1)'. - * a chess knight has eight possible moves it can make, as illustrated below - * [see image]. each move is two cells in a cardinal direction, then one cell in - * an orthogonal direction. - */ - -class Solution { -public: - double knightProbability(int n, int k, int row, int col) { - unordered_map<int, unordered_map<int, unordered_map<int, double>>> dp; - if (dp.count(row) && dp[row].count(col) && dp[row][row].count(k)) - return dp[row][col][k]; - if (row < 0 || row >= n || col < 0 || col >= n) - return 0; - if (!k) - return 1; - double total = knightProbability(n, k - 1, row - 1, col - 2) + - knightProbability(n, k - 1, row - 2, col - 1) + - knightProbability(n, k - 1, row - 1, col + 2) + - knightProbability(n, k - 1, row - 2, col + 1) + - knightProbability(n, k - 1, row + 1, col + 2) + - knightProbability(n, k - 1, row + 2, col + 1) + - knightProbability(n, k - 1, row + 1, col - 2) + - knightProbability(n, k - 1, row + 2, col - 1); - double ans = total / 8; - dp[row][col][k] = ans; - return ans; - } -}; - -int main() { - Solution obj; - printf("%f\n", obj.knightProbability(3, 2, 0, 0)); // expect: 0.06250 - printf("%f\n", obj.knightProbability(1, 0, 0, 0)); // expect: 1.00000 -} |