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#include "leetcode.h"
class Solution {
public:
vector<int> findBall(vvd(int) & grid) {
int m = grid.size(), n = grid[0].size();
vvd(int) ugrid(m * 3, vector<int>(n * 3));
for (auto i = 0; i < m; i++)
for (auto j = 0; j < n; j++) {
ugrid[i * 3 + 1][j * 3 + 1] = 1;
ugrid[i * 3][j * 3] = ugrid[i * 3 + 2][j * 3 + 2] = grid[i][j] == 1;
ugrid[i * 3][j * 3 + 2] = ugrid[i * 3 + 2][j * 3] = grid[i][j] != 1;
}
vector<int> ans;
for (auto i = 0; i < n; ++i)
ans.push_back(drop(i * 3 + 1, ugrid, m * 3, n * 3));
return ans;
}
private:
vector<pair<int, int>> dir{{1, 0}, {0, -1}, {0, 1}};
int drop(int pos, vvd(int) & ugrid, int m, int n) {
queue<pair<int, int>> qp;
qp.push({0, pos});
while (!qp.empty()) {
auto [i, j] = qp.front();
qp.pop();
if (i == m - 1)
return j / 3;
ugrid[i][j] = 1;
for (auto [di, dj] : dir)
if (j + dj >= 0 && j + dj < n && !ugrid[i + di][j + dj]) {
qp.push({i + di, j + dj});
break;
}
}
return -1;
}
};
int main() {
Solution obj;
vvd(int) grid = {{1, 1, 1, -1, -1},
{1, 1, 1, -1, -1},
{-1, -1, -1, 1, 1},
{1, 1, 1, 1, -1},
{-1, -1, -1, -1, -1}};
for (auto i : obj.findBall(grid))
cout << i << ' ';
}
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