Create find-all-groups-of-farmland.cpp

Author: kamyu104

C++/find-all-groups-of-farmland.cpp

@@ -0,0 +1,30 @@
+// Time:  O(m * n)
+// Space: O(1)
+
+class Solution {
+public:
+    vector<vector<int>> findFarmland(vector<vector<int>>& land) {
+        vector<vector<int>> result;
+        for (int i = 0; i < size(land); ++i) {
+            for (int j = 0; j < size(land[0]); ++j) {
+                if (land[i][j] != 1) {
+                    continue;
+                }
+                int ni = i, nj = j;
+                while (ni + 1 < size(land) && land[ni + 1][j]) {
+                    ++ni;
+                }
+                while (nj + 1 < size(land[0]) && land[i][nj + 1]) {
+                    ++nj;
+                }
+                for (int r = i; r <= ni; ++r) {
+                    for (int c = j; c <= nj; ++c) {
+                        land[r][c] = -1;
+                    }
+                }
+                result.push_back({i, j, ni, nj});
+            }
+        }
+        return result;
+    }
+};