add 934

src/0934-Shortest-Bridge/0934.cpp

@@ -0,0 +1,70 @@
+#include <iostream>
+#include <queue>
+using namespace std;
+
+static int x = []() {std::ios::sync_with_stdio(false); cin.tie(0); return 0; }();
+class Solution 
+{
+private:
+    vector<pair<int, int>> edges;
+    void getEdges(vector<vector<int>>& A, int x, int y) 
+    {
+        if (x < 0 || y < 0 || x >= A.size() || 
+            y >= A[0].size() || A[x][y] != 1) return;
+        if ((x > 0 && A[x-1][y] == 0) || (y+1 < A[0].size() && A[x][y+1] == 0) ||
+           (x+1 < A.size() && A[x+1][y] == 0) || (y > 0 && A[x][y-1] == 0)) 
+            edges.push_back(make_pair(x, y));
+        A[x][y] = 2;
+        getEdges(A, x-1, y);
+        getEdges(A, x, y+1);
+        getEdges(A, x+1, y);
+        getEdges(A, x, y-1);
+    }
+    bool valid(vector<vector<int>>& A, vector<pair<int, int>>& next, int x, int y) 
+    {
+        if (x < 0 || y < 0 || x >= A.size() || 
+            y >= A[0].size() || A[x][y] == 2) 
+            return false;
+        if (A[x][y] == 1) return true;
+        A[x][y] = 2;
+        next.push_back(make_pair(x, y));
+        return false;
+    }
+public:
+    int shortestBridge(vector<vector<int>>& A) 
+    {
+        for (int i=0; i<A.size(); ++i) 
+        {
+            for (int j=0; j<A[i].size(); ++j) 
+            {
+                if (A[i][j]) 
+                {
+                    getEdges(A, i, j);
+                    goto forward;
+                }
+            }
+        }
+    forward:
+        int step = 0;
+        while (!edges.empty()) 
+        {
+            step += 1;
+            vector<pair<int, int>> next;
+            for (int i=0; i<edges.size(); ++i) 
+            {
+                int x = edges[i].first;
+                int y = edges[i].second;
+                if (valid(A, next, x-1, y) || valid(A, next, x, y+1) ||
+                    valid(A, next, x+1, y) || valid(A, next, x, y-1)) 
+                    goto end;
+            }
+            edges = next;
+        }
+    end:
+        return step - 1;
+    }
+};
+int main()
+{
+    return 0;
+}

src/0934-Shortest-Bridge/0934.py

@@ -0,0 +1,63 @@
+class Solution:
+    def shortestBridge(self, A):
+        """
+        :type A: List[List[int]]
+        :rtype: int
+        """
+        x, y, r, c = 0, 0, len(A), len(A[0])
+        for i in range(r):
+            for j in range(c):
+                if A[i][j] == 1:
+                    x, y = i, j
+                    break
+            else:
+                continue
+            break
+
+        d = [(-1, 0), (0, 1), (1, 0), (0, -1)]
+        visited = [[0]*c for _ in range(r)]
+        islandA, result = list(), 0
+        def _floodfill(i, j):
+            if 0 <= i < r and 0 <= j < c and not visited[i][j] and A[i][j] == 1:
+                visited[i][j] = 1
+                islandA.append((i, j))
+                for k in range(4):
+                    _floodfill(i + d[k][0], j + d[k][1])
+
+        _floodfill(x, y)
+        while islandA:
+            stack = list()
+            for i, j in islandA:
+                if i - 1 >= 0 and not visited[i-1][j]:
+                    if A[i-1][j] == 1:
+                        return result
+                    else:
+                        stack.append((i-1, j))
+                        visited[i-1][j] = 1
+                if i + 1 < r and not visited[i+1][j]:
+                    if A[i+1][j] == 1:
+                        return result
+                    else:
+                        stack.append((i+1, j))
+                        visited[i+1][j] = 1
+                if j - 1 >= 0 and not visited[i][j-1]:
+                    if A[i][j-1] == 1:
+                        return result
+                    else:
+                        stack.append((i, j-1))
+                        visited[i][j-1] = 1
+                if j + 1 < c and not visited[i][j+1]:
+                    if A[i][j+1] == 1:
+                        return result
+                    else:
+                        stack.append((i, j+1))
+                        visited[i][j+1] = 1
+            islandA = stack
+            result += 1
+
+        return result
+
+
+if __name__ == "__main__":
+    A = [[0,1,0],[0,0,0],[0,0,1]]
+    print(Solution().shortestBridge(A))