leetcode

1 Random Problem

2 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/ Problems/2257.cpp b/ Problems/2257.cpp

@@ -0,0 +1,31 @@

class Solution {

public:

int countUnguarded(const int n, const int m, const vector<vector<int>> &guards,

const vector<vector<int>> &walls) const {

const auto idx = [m](int x, int y) { return x * m + y; };

bitset<100001> stop = 0, seen = 0;

for (const auto &wall : walls)

stop.set(idx(wall[0], wall[1]));

for (const auto &guard : guards)

stop.set(idx(guard[0], guard[1]));

static const int offset[] = {-1, 0, 1, 0, -1};

int res = m * n - size(walls) - size(guards);

for (const auto &guard : guards) {

for (int k = 0; k < 4; k++) {

int x = guard[0] + offset[k], y = guard[1] + offset[k + 1];

while (x >= 0 && x < n && y >= 0 && y < m) {

const int index = idx(x, y);

if (stop.test(index)) break;

if (!seen.test(index)) res--;

seen.set(index);

x += offset[k], y += offset[k + 1];

}

}

}

return res;

}

};

diff --git a/ README.md b/ README.md

@@ -1030,6 +1030,7 @@ for solving problems. | 2244 | Medium | [Minimum Rounds to Complete All Tasks](Problems/2244.cpp) | | 2246 | Hard | [Longest Path With Different Adjacent Characters](Problems/2246.cpp) | | 2251 | Hard | [Number of Flowers in Full Bloom](Problems/2251.cpp) |

| 2257 | Medium | [Count Unguarded Cells in the Grid](Problems/2257.cpp) |

| 2264 | Easy | [Largest 3-Same-Digit Number in String](Problems/2264.cpp) | | 2265 | Medium | [Count Nodes Equal to Average of Subtree](Problems/2265.cpp) | | 2265 | Medium | [Count Nodes Equal to Average of Subtree](Problems/2265.cpp) |