Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

feat: add solutions to lc problem: No.1559 #3558

Merged
merged 1 commit into from
Sep 24, 2024
Merged

feat: add solutions to lc problem: No.1559 #3558

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
557 changes: 422 additions & 135 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/README.md
View file
Open in desktop

Large diffs are not rendered by default.

557 changes: 422 additions & 135 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/README_EN.md
View file
Open in desktop

Large diffs are not rendered by default.

67 changes: 39 additions & 28 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/Solution.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,28 +1,39 @@
class Solution {
public:
vector<int> p;

bool containsCycle(vector<vector<char>>& grid) {
int m = grid.size(), n = grid[0].size();
p.resize(m * n);
for (int i = 0; i < p.size(); ++i) p[i] = i;
vector<int> dirs = {0, 1, 0};
for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j) {
for (int k = 0; k < 2; ++k) {
int x = i + dirs[k], y = j + dirs[k + 1];
if (x < m && y < n && grid[x][y] == grid[i][j]) {
if (find(x * n + y) == find(i * n + j)) return 1;
p[find(x * n + y)] = find(i * n + j);
}
}
}
}
return 0;
}

int find(int x) {
if (p[x] != x) p[x] = find(p[x]);
return p[x];
}
};
class Solution {
public:
bool containsCycle(vector<vector<char>>& grid) {
int m = grid.size(), n = grid[0].size();
vector<vector<bool>> vis(m, vector<bool>(n));
const vector<int> dirs = {-1, 0, 1, 0, -1};

for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j) {
if (!vis[i][j]) {
queue<array<int, 4>> q;
q.push({i, j, -1, -1});
vis[i][j] = true;

while (!q.empty()) {
auto p = q.front();
q.pop();
int x = p[0], y = p[1], px = p[2], py = p[3];

for (int k = 0; k < 4; ++k) {
int nx = x + dirs[k], ny = y + dirs[k + 1];
if (nx >= 0 && nx < m && ny >= 0 && ny < n) {
if (grid[nx][ny] != grid[x][y] || (nx == px && ny == py)) {
continue;
}
if (vis[nx][ny]) {
return true;
}
q.push({nx, ny, x, y});
vis[nx][ny] = true;
}
}
}
}
}
}
return false;
}
};
67 changes: 38 additions & 29 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/Solution.go
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,29 +1,38 @@
func containsCycle(grid [][]byte) bool {
m, n := len(grid), len(grid[0])
p := make([]int, m*n)
for i := range p {
p[i] = i
}
var find func(x int) int
find = func(x int) int {
if p[x] != x {
p[x] = find(p[x])
}
return p[x]
}
dirs := []int{1, 0, 1}
for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
for k := 0; k < 2; k++ {
x, y := i+dirs[k], j+dirs[k+1]
if x < m && y < n && grid[x][y] == grid[i][j] {
if find(x*n+y) == find(i*n+j) {
return true
}
p[find(x*n+y)] = find(i*n + j)
}
}
}
}
return false
}
func containsCycle(grid [][]byte) bool {
m, n := len(grid), len(grid[0])
vis := make([][]bool, m)
for i := range vis {
vis[i] = make([]bool, n)
}
dirs := []int{-1, 0, 1, 0, -1}

for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
if !vis[i][j] {
q := [][]int{{i, j, -1, -1}}
vis[i][j] = true

for len(q) > 0 {
p := q[0]
q = q[1:]
x, y, px, py := p[0], p[1], p[2], p[3]

for k := 0; k < 4; k++ {
nx, ny := x+dirs[k], y+dirs[k+1]
if nx >= 0 && nx < m && ny >= 0 && ny < n {
if grid[nx][ny] != grid[x][y] || (nx == px && ny == py) {
continue
}
if vis[nx][ny] {
return true
}
q = append(q, []int{nx, ny, x, y})
vis[nx][ny] = true
}
}
}
}
}
}
return false
}
69 changes: 34 additions & 35 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/Solution.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,35 +1,34 @@
class Solution {
private int[] p;

public boolean containsCycle(char[][] grid) {
int m = grid.length;
int n = grid[0].length;
p = new int[m * n];
for (int i = 0; i < p.length; ++i) {
p[i] = i;
}
int[] dirs = {0, 1, 0};
for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j) {
for (int k = 0; k < 2; ++k) {
int x = i + dirs[k];
int y = j + dirs[k + 1];
if (x < m && y < n && grid[i][j] == grid[x][y]) {
if (find(x * n + y) == find(i * n + j)) {
return true;
}
p[find(x * n + y)] = find(i * n + j);
}
}
}
}
return false;
}

private int find(int x) {
if (p[x] != x) {
p[x] = find(p[x]);
}
return p[x];
}
}
class Solution {
public boolean containsCycle(char[][] grid) {
int m = grid.length, n = grid[0].length;
boolean[][] vis = new boolean[m][n];
final int[] dirs = {-1, 0, 1, 0, -1};
for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j) {
if (!vis[i][j]) {
Deque<int[]> q = new ArrayDeque<>();
q.offer(new int[] {i, j, -1, -1});
vis[i][j] = true;
while (!q.isEmpty()) {
int[] p = q.poll();
int x = p[0], y = p[1], px = p[2], py = p[3];
for (int k = 0; k < 4; ++k) {
int nx = x + dirs[k], ny = y + dirs[k + 1];
if (nx >= 0 && nx < m && ny >= 0 && ny < n) {
if (grid[nx][ny] != grid[x][y] || (nx == px && ny == py)) {
continue;
}
if (vis[nx][ny]) {
return true;
}
q.offer(new int[] {nx, ny, x, y});
vis[nx][ny] = true;
}
}
}
}
}
}
return false;
}
}
40 changes: 21 additions & 19 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/Solution.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,26 +3,28 @@
* @return {boolean}
*/
var containsCycle = function (grid) {
const m = grid.length;
const n = grid[0].length;
let p = Array.from({ length: m * n }, (_, i) => i);
function find(x) {
if (p[x] != x) {
p[x] = find(p[x]);
}
return p[x];
}
const dirs = [0, 1, 0];
for (let i = 0; i < m; ++i) {
for (let j = 0; j < n; ++j) {
for (let k = 0; k < 2; ++k) {
const x = i + dirs[k];
const y = j + dirs[k + 1];
if (x < m && y < n && grid[x][y] == grid[i][j]) {
if (find(x * n + y) == find(i * n + j)) {
return true;
const [m, n] = [grid.length, grid[0].length];
const vis = Array.from({ length: m }, () => Array(n).fill(false));
const dirs = [-1, 0, 1, 0, -1];
for (let i = 0; i < m; i++) {
for (let j = 0; j < n; j++) {
if (!vis[i][j]) {
const q = [[i, j, -1, -1]];
vis[i][j] = true;
for (const [x, y, px, py] of q) {
for (let k = 0; k < 4; k++) {
const [nx, ny] = [x + dirs[k], y + dirs[k + 1]];
if (nx >= 0 && nx < m && ny >= 0 && ny < n) {
if (grid[nx][ny] !== grid[x][y] || (nx === px && ny === py)) {
continue;
}
if (vis[nx][ny]) {
return true;
}
q.push([nx, ny, x, y]);
vis[nx][ny] = true;
}
}
p[find(x * n + y)] = find(i * n + j);
}
}
}
Expand Down
41 changes: 23 additions & 18 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/Solution.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,18 +1,23 @@
class Solution:
def containsCycle(self, grid: List[List[str]]) -> bool:
def find(x):
if p[x] != x:
p[x] = find(p[x])
return p[x]

m, n = len(grid), len(grid[0])
p = list(range(m * n))
for i in range(m):
for j in range(n):
for a, b in [[0, 1], [1, 0]]:
x, y = i + a, j + b
if x < m and y < n and grid[x][y] == grid[i][j]:
if find(x * n + y) == find(i * n + j):
return True
p[find(x * n + y)] = find(i * n + j)
return False
class Solution:
def containsCycle(self, grid: List[List[str]]) -> bool:
m, n = len(grid), len(grid[0])
vis = [[False] * n for _ in range(m)]
dirs = (-1, 0, 1, 0, -1)
for i, row in enumerate(grid):
for j, x in enumerate(row):
if vis[i][j]:
continue
vis[i][j] = True
q = [(i, j, -1, -1)]
while q:
x, y, px, py = q.pop()
for dx, dy in pairwise(dirs):
nx, ny = x + dx, y + dy
if 0 <= nx < m and 0 <= ny < n:
if grid[nx][ny] != grid[i][j] or (nx == px and ny == py):
continue
if vis[nx][ny]:
return True
vis[nx][ny] = True
q.append((nx, ny, x, y))
return False
97 changes: 41 additions & 56 deletions solution/1500-1599/1559.Detect Cycles in 2D Grid/Solution.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,56 +1,41 @@
impl Solution {
#[allow(dead_code)]
pub fn contains_cycle(grid: Vec<Vec<char>>) -> bool {
let n = grid.len();
let m = grid[0].len();
let mut d_set: Vec<usize> = vec![0; n * m];

// Initialize the disjoint set
for i in 0..n * m {
d_set[i] = i;
}

// Traverse the grid
for i in 0..n {
for j in 0..m {
if i + 1 < n && grid[i + 1][j] == grid[i][j] {
// Check the below cell
let p_curr = Self::find(i * m + j, &mut d_set);
let p_below = Self::find((i + 1) * m + j, &mut d_set);
if p_curr == p_below {
return true;
}
// Otherwise, union the two cells
Self::union(p_curr, p_below, &mut d_set);
}
// Same to the right cell
if j + 1 < m && grid[i][j + 1] == grid[i][j] {
let p_curr = Self::find(i * m + j, &mut d_set);
let p_right = Self::find(i * m + (j + 1), &mut d_set);
if p_curr == p_right {
return true;
}
// Otherwise, union the two cells
Self::union(p_curr, p_right, &mut d_set);
}
}
}

false
}

#[allow(dead_code)]
fn find(x: usize, d_set: &mut Vec<usize>) -> usize {
if d_set[x] != x {
d_set[x] = Self::find(d_set[x], d_set);
}
d_set[x]
}

#[allow(dead_code)]
fn union(x: usize, y: usize, d_set: &mut Vec<usize>) {
let p_x = Self::find(x, d_set);
let p_y = Self::find(y, d_set);
d_set[p_x] = p_y;
}
}
impl Solution {
pub fn contains_cycle(grid: Vec<Vec<char>>) -> bool {
let m = grid.len();
let n = grid[0].len();
let mut vis = vec![vec![false; n]; m];
let dirs = vec![-1, 0, 1, 0, -1];

for i in 0..m {
for j in 0..n {
if !vis[i][j] {
let mut q = vec![(i as isize, j as isize, -1, -1)];
vis[i][j] = true;

while !q.is_empty() {
let (x, y, px, py) = q.pop().unwrap();

for k in 0..4 {
let nx = x + dirs[k];
let ny = y + dirs[k + 1];
if nx >= 0 && nx < m as isize && ny >= 0 && ny < n as isize {
let nx = nx as usize;
let ny = ny as usize;
if grid[nx][ny] != grid[x as usize][y as usize]
|| (nx == px as usize && ny == py as usize)
{
continue;
}
if vis[nx][ny] {
return true;
}
q.push((nx as isize, ny as isize, x, y));
vis[nx][ny] = true;
}
}
}
}
}
}
false
}
}
Loading
Loading