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Commit 32e7de5

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feat: add solution for surrounded regions
1 parent 4d7616b commit 32e7de5

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4 files changed

+88
-2
lines changed

4 files changed

+88
-2
lines changed
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from typing import List
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def solve(board: List[List[str]]) -> None:
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"""
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Do not return anything, modify board in-place instead.
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"""
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ROWS, COLS = len(board), len(board[0])
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def dfs(r, c):
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if r < 0 or c < 0 or r == ROWS or c == COLS or board[r][c] != "O":
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return
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board[r][c] = "#"
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dfs(r - 1, c)
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dfs(r + 1, c)
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dfs(r, c - 1)
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dfs(r, c + 1)
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for r in range(ROWS):
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dfs(r, 0)
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dfs(r, COLS - 1)
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for c in range(COLS):
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dfs(0, c)
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dfs(ROWS - 1, c)
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for r in range(ROWS):
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for c in range(COLS):
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if board[r][c] == "#":
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board[r][c] = "O"
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elif board[r][c] == "O":
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board[r][c] = "X"
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"""
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Algorithm - DFS
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Time complexity: O(m*n)
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Space complexity: O(m*n) for the call stack
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"""
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board = [["X","X","X","X"], ["X","O","O","X"], ["X","X","O","X"], ["X","O","X","X"]]
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solve(board)
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print(board)
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assert board == [["X","X","X","X"], ["X","X","X","X"], ["X","X","X","X"], ["X","O","X","X"]]

‎src/medium/surrounded_regions.rs‎

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#![allow(dead_code)]
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pub fn solve(board: &mut Vec<Vec<char>>) {
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let rows = board.len();
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let cols = board[0].len();
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fn dfs(board: &mut Vec<Vec<char>>, r: usize, c: usize) {
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let rows = board.len();
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let cols = board[0].len();
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if r >= rows || c >= cols || board[r][c] != 'O' {
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return;
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}
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board[r][c] = '#';
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if r > 0 {
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dfs(board, r - 1, c);
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}
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if c > 0 {
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dfs(board, r, c - 1);
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}
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dfs(board, r + 1, c);
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dfs(board, r, c + 1);
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}
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for r in 0..rows {
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dfs(board, r, 0);
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dfs(board, r, cols - 1);
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}
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for c in 0..cols {
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dfs(board, 0, c);
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dfs(board, rows - 1, c);
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}
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for r in 0..rows {
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for c in 0..cols {
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if board[r][c] == '#' {
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board[r][c] = 'O';
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} else if board[r][c] == 'O' {
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board[r][c] = 'X';
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}
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}
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}
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}

‎src/readme.md‎

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@@ -70,7 +70,7 @@
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- [x] [102. Binary tree level order traversal](../src/medium/binary_tree_level_order_traversal.rs) -> [Problem Description](../src/medium/readme.md#102-binary-tree-level-order-traversal)
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- [x] [105. Construct binary tree from preorder and inorder traversal](../src/medium/construct_binary_tree_from_preorder_and_inorder_traversal.rs) -> [Problem Description](../src/medium/readme.md#105-construct-binary-tree-from-preorder-and-inorder-traversal)
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- [x] [128. Longest consecutive sequence](../src/medium/longest_consecutive_sequence.rs) -> [Problem Description](../src/medium/readme.md#128-longest-consecutive-sequence)
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- [] [130. Surrounded regions](../src/medium/surrounded_regions.rs) -> [Problem Description](../src/medium/readme.md#130-surrounded-regions)
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- [x] [130. Surrounded regions](../src/medium/surrounded_regions.rs) -> [Problem Description](../src/medium/readme.md#130-surrounded-regions)
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- [x] [131. Palindrome partitioning](../src/medium/palindrome_partitioning.rs) -> [Problem Description](../src/medium/readme.md#131-palindrome-partitioning)
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- [x] [133. Clone graph](../src/medium/clone_graph.rs) -> [Problem Description](../src/medium/readme.md#133-clone-graph)
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- [x] [138. Copy list with random pointer PYTHON Solution](../alternative/medium/copy_list_with_random_pointer.py) -> [Problem Description](../src/medium/readme.md#138-copy-list-with-random-pointer)

‎theory/categories/6.graphs/readme.md‎

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@@ -19,7 +19,7 @@ A graph can be implemented using an adjacency list or an adjacency matrix.
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- [x] [Clone Graph](https://leetcode.com/problems/clone-graph/) | Medium | [Solution](../../../src/medium/clone_graph.rs) | [Problem Description](../../../src/medium/readme.md#133-clone-graph)
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- [x] [Max Area of Island](https://leetcode.com/problems/max-area-of-island/) | Medium | [Solution](../../../src/medium/max_area_of_island.rs) | [Problem Description](../../../src/medium/readme.md#695-max-area-of-island)
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- [x] [Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/) | Medium | [Solution](../../../src/medium/pacific_atlantic_water_flow.rs) | [Problem Description](../../../src/medium/readme.md#417-pacific-atlantic-water-flow)
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- [] [Surrounded Regions](https://leetcode.com/problems/surrounded-regions/) | Medium | [Solution](../../../src/medium/surrounded_regions.rs) | [Problem Description](../../../src/medium/readme.md#130-surrounded-regions)
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- [x] [Surrounded Regions](https://leetcode.com/problems/surrounded-regions/) | Medium | [Solution](../../../src/medium/surrounded_regions.rs) | [Problem Description](../../../src/medium/readme.md#130-surrounded-regions)
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- [ ] [Rotten Oranges](https://leetcode.com/problems/rotting-oranges/) | Medium | [Solution](../../../src/medium/rotten_oranges.rs) | [Problem Description](../../../src/medium/readme.md#994-rotting-oranges)
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- [ ] [Walls and Gates](https://leetcode.com/problems/walls-and-gates/) | Medium | [Solution](../../../src/medium/walls_and_gates.rs) | [Problem Description](../../../src/medium/readme.md#286-walls-and-gates)
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- [ ] [Course Schedule](https://leetcode.com/problems/course-schedule/) | Medium | [Solution](../../../src/medium/course_schedule.rs) | [Problem Description](../../../src/medium/readme.md#207-course-schedule)

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