diff options
Diffstat (limited to 'other/snakes_ladders.cpp')
-rw-r--r-- | other/snakes_ladders.cpp | 47 |
1 files changed, 0 insertions, 47 deletions
diff --git a/other/snakes_ladders.cpp b/other/snakes_ladders.cpp deleted file mode 100644 index 160b473..0000000 --- a/other/snakes_ladders.cpp +++ /dev/null @@ -1,47 +0,0 @@ -// 909. Snakes and Ladders -#include "leetcode.h" - -typedef pair<int, int> pii; -class Solution { -public: - int snakesAndLadders(vvd & board) { - int rows = board.size(), cols = board[0].size(); - int target = rows * cols, r, c, p; - vector<int> visited(rows * cols + 1); // cells on board starting from 1 - priority_queue<pii, vector<pii>, greater<pii>> pq; - pq.push(make_pair(0, 1)); - visited[1] = true; - while (pq.size()) { - auto stepPos = pq.top(); - pq.pop(); - int s = stepPos.first / 1000 + 1; - for (int i = 1; i <= 6; i++) { - auto p = stepPos.second + i; - if (visited[p]) - continue; - visited[p] = true; - r = rows - (p - 1) / cols - 1; - c = (p - 1) % cols; - if ((rows - r - 1) % 2) - c = cols - c - 1; - int ladder = board[r][c]; - if (ladder > 0 && ladder <= target) - p = ladder; - if (p == target) - return s; - pq.push(make_pair(s * 1000 + 500 - p, p)); - } - } - return -1; - } -}; - -int main() { - Solution obj; - vvd board1 = {{-1, -1, -1, -1, -1, -1}, {-1, -1, -1, -1, -1, -1}, - {-1, -1, -1, -1, -1, -1}, {-1, 35, -1, -1, 13, -1}, - {-1, -1, -1, -1, -1, -1}, {-1, 15, -1, -1, -1, -1}}; - vvd board2 = {{-1, -1}, {-1, 3}}; - cout << obj.snakesAndLadders(board1) << endl; // expect: 4 - cout << obj.snakesAndLadders(board2) << endl; // expect: 1 -} |