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-rw-r--r--other/far_from_land.cpp44
1 files changed, 44 insertions, 0 deletions
diff --git a/other/far_from_land.cpp b/other/far_from_land.cpp
new file mode 100644
index 0000000..651b8a7
--- /dev/null
+++ b/other/far_from_land.cpp
@@ -0,0 +1,44 @@
+#include "leetcode.h"
+
+class Solution {
+public:
+ int maxDistance(vector<vector<int>> &grid) {
+ int ans = -1;
+ if (grid.empty() || grid[0].empty())
+ return ans;
+
+ vector<vector<int>> gridValues(grid.size(),
+ vector<int>(grid[0].size(), INT_MAX));
+ queue<pair<int, int>> q;
+
+ for (int i = 0; i < grid.size(); ++i) {
+ for (int j = 0; j < grid[0].size(); ++j) {
+ if (grid[i][j] == 1) {
+ q.push(make_pair(i, j));
+ gridValues[i][j] = 0;
+ }
+ }
+ }
+ if (q.empty())
+ return -1;
+ vector<int> dx({0, 1, 0, -1}), dy({1, 0, -1, 0});
+ while (!q.empty()) {
+ auto pos = q.front();
+ q.pop();
+ for (int i = 0; i < 4; ++i) {
+ int x = pos.first + dx[i], y = pos.second + dy[i];
+ if (x >= 0 && x < grid.size() && y >= 0 && y < grid[0].size()) {
+ if (gridValues[x][y] == INT_MAX)
+ q.push(make_pair(x, y));
+ gridValues[x][y] =
+ min(gridValues[x][y], gridValues[pos.first][pos.second] + 1);
+ }
+ }
+ }
+ for (int i = 0; i < grid.size(); ++i)
+ for (int j = 0; j < grid[0].size(); ++j)
+ if (grid[i][j] == 0)
+ ans = max(ans, gridValues[i][j]);
+ return ans;
+ }
+};