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Merge branch 'master' of github.com:youngyangyang04/leetcode-master

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programmercarl
2023-09-05 10:22:44 +08:00
parent 7e7e0cd0c7 ab90e74945
commit d0f7d4698e
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41
problems/0200.岛屿数量.广搜版.md
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@ -240,6 +240,47 @@ class Solution:
```
### Rust
```rust
use std::collections::VecDeque;
impl Solution {
const DIRECTIONS: [(i32, i32); 4] = [(0, 1), (1, 0), (-1, 0), (0, -1)];
pub fn num_islands(grid: Vec<Vec<char>>) -> i32 {
let mut visited = vec![vec![false; grid[0].len()]; grid.len()];
let mut res = 0;
for (i, chars) in grid.iter().enumerate() {
for (j, &c) in chars.iter().enumerate() {
if !visited[i][j] && c == '1' {
res += 1;
Self::bfs(&grid, &mut visited, (i as i32, j as i32));
}
}
}
res
}
pub fn bfs(grid: &Vec<Vec<char>>, visited: &mut Vec<Vec<bool>>, (x, y): (i32, i32)) {
let mut queue = VecDeque::new();
queue.push_back((x, y));
visited[x as usize][y as usize] = true;
while let Some((cur_x, cur_y)) = queue.pop_front() {
for (dx, dy) in Self::DIRECTIONS {
let (nx, ny) = (cur_x + dx, cur_y + dy);
if nx < 0 || nx >= grid.len() as i32 || ny < 0 || ny >= grid[0].len() as i32 {
continue;
}
let (nx, ny) = (nx as usize, ny as usize);
if grid[nx][ny] == '1' && !visited[nx][ny] {
visited[nx][ny] = true;
queue.push_back((nx as i32, ny as i32));
}
}
}
}
}
```
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36
problems/0200.岛屿数量.深搜版.md
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@ -279,6 +279,42 @@ class Solution:
return result
```
Rust:
```rust
impl Solution {
const DIRECTIONS: [(i32, i32); 4] = [(0, 1), (1, 0), (-1, 0), (0, -1)];
pub fn num_islands(grid: Vec<Vec<char>>) -> i32 {
let mut visited = vec![vec![false; grid[0].len()]; grid.len()];
let mut res = 0;
for (i, chars) in grid.iter().enumerate() {
for (j, &c) in chars.iter().enumerate() {
if !visited[i][j] && c == '1' {
res += 1;
Self::dfs(&grid, &mut visited, (i as i32, j as i32));
}
}
}
res
}
pub fn dfs(grid: &Vec<Vec<char>>, visited: &mut Vec<Vec<bool>>, (x, y): (i32, i32)) {
for (dx, dy) in Self::DIRECTIONS {
let (nx, ny) = (x + dx, y + dy);
if nx < 0 || nx >= grid.len() as i32 || ny < 0 || ny >= grid[0].len() as i32 {
continue;
}
let (nx, ny) = (nx as usize, ny as usize);
if grid[nx][ny] == '1' && !visited[nx][ny] {
visited[nx][ny] = true;
Self::dfs(grid, visited, (nx as i32, ny as i32));
}
}
}
}
```
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73
problems/0332.重新安排行程.md
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@ -345,6 +345,79 @@ class Solution {
}
```
```java
/* 该方法是对第二个方法的改进，主要变化在于将某点的所有终点变更为链表的形式，优点在于
1.添加终点时直接在对应位置添加节点，避免了TreeMap增元素时的频繁调整
2.同时每次对终点进行增加删除查找时直接通过下标操作，避免hashMap反复计算hash*/
class Solution {
//key为起点，value是有序的终点的列表
Map<String, LinkedList<String>> ticketMap = new HashMap<>();
LinkedList<String> result = new LinkedList<>();
int total;
public List<String> findItinerary(List<List<String>> tickets) {
total = tickets.size() + 1;
//遍历tickets，存入ticketMap中
for (List<String> ticket : tickets) {
addNew(ticket.get(0), ticket.get(1));
}
deal("JFK");
return result;
}
boolean deal(String currentLocation) {
result.add(currentLocation);
//机票全部用完，找到最小字符路径
if (result.size() == total) {
return true;
}
//当前位置的终点列表
LinkedList<String> targetLocations = ticketMap.get(currentLocation);
//没有从当前位置出发的机票了，说明这条路走不通
if (targetLocations != null && !targetLocations.isEmpty()) {
//终点列表中遍历到的终点
String targetLocation;
//遍历从当前位置出发的机票
for (int i = 0; i < targetLocations.size(); i++) {
targetLocation = targetLocations.get(i);
//删除终点列表中当前的终点
targetLocations.remove(i);
//递归
if (deal(targetLocation)) {
return true;
}
//路线走不通，将机票重新加回去
targetLocations.add(i, targetLocation);
result.removeLast();
}
}
return false;
}
/**
* 在map中按照字典顺序添加新元素
*
* @param start 起点
* @param end 终点
*/
void addNew(String start, String end) {
LinkedList<String> startAllEnd = ticketMap.getOrDefault(start, new LinkedList<>());
if (!startAllEnd.isEmpty()) {
for (int i = 0; i < startAllEnd.size(); i++) {
if (end.compareTo(startAllEnd.get(i)) < 0) {
startAllEnd.add(i, end);
return;
}
}
startAllEnd.add(startAllEnd.size(), end);
} else {
startAllEnd.add(end);
ticketMap.put(start, startAllEnd);
}
}
}
```
### Python
回溯 使用used数组

32
problems/0496.下一个更大元素I.md
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@ -396,25 +396,33 @@ function nextGreaterElement(nums1: number[], nums2: number[]): number[] {
### Rust
```rust
use std::collections::HashMap;
impl Solution {
pub fn next_greater_element(nums1: Vec<i32>, nums2: Vec<i32>) -> Vec<i32> {
let mut ans = vec![-1; nums1.len()];
use std::collections::HashMap;
let mut map = HashMap::new();
for (idx, &i) in nums1.iter().enumerate() {
map.insert(i, idx);
let (mut res, mut map) = (vec![-1; nums1.len()], HashMap::new());
if nums1.is_empty() {
return res;
}
nums1.into_iter().enumerate().for_each(|(v, k)| {
map.insert(k, v);
});
let mut stack = vec![];
for (idx, &i) in nums2.iter().enumerate() {
while !stack.is_empty() && nums2[*stack.last().unwrap()] < i {
let pos = stack.pop().unwrap();
if let Some(&jdx) = map.get(&nums2[pos]) {
ans[jdx] = i;
for (i, &value) in nums2.iter().enumerate() {
while let Some(&top) = stack.last() {
if value <= nums2[top] {
break;
}
let stacked_index = stack.pop().unwrap();
if let Some(&mapped_index) = map.get(&nums2[stacked_index]) {
res[mapped_index] = value;
}
}
stack.push(idx);
stack.push(i);
}
ans
res
}
}
```

22
problems/0503.下一个更大元素II.md
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@ -293,6 +293,28 @@ impl Solution {
}
```
> 版本二：
```rust
impl Solution {
pub fn next_greater_elements(nums: Vec<i32>) -> Vec<i32> {
let (mut stack, mut res) = (vec![], vec![-1; nums.len()]);
for i in 0..nums.len() * 2 {
while let Some(&top) = stack.last() {
if nums[i % nums.len()] <= nums[top] {
break;
}
let saved_index = stack.pop().unwrap();
res[saved_index] = nums[i % nums.len()];
}
stack.push(i % nums.len());
}
res
}
}
```
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22
problems/0797.所有可能的路径.md
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@ -217,7 +217,29 @@ class Solution:
self.path.pop() # 回溯
```
### Rust
```rust
impl Solution {
pub fn all_paths_source_target(graph: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
let (mut res, mut path) = (vec![], vec![0]);
Self::dfs(&graph, &mut path, &mut res, 0);
res
}
pub fn dfs(graph: &Vec<Vec<i32>>, path: &mut Vec<i32>, res: &mut Vec<Vec<i32>>, node: usize) {
if node == graph.len() - 1 {
res.push(path.clone());
return;
}
for &v in &graph[node] {
path.push(v);
Self::dfs(graph, path, res, v as usize);
path.pop();
}
}
}
```
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