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feat: add solutions to lc problems: No.2810~2812 #1476

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18 changes: 18 additions & 0 deletions solution/2800-2899/2810.Faulty Keyboard/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -158,6 +158,24 @@ function finalString(s: string): string {
}
```

### **Rust**

```rust
impl Solution {
pub fn final_string(s: String) -> String {
let mut t = Vec::new();
for c in s.chars() {
if c == 'i' {
t.reverse();
} else {
t.push(c);
}
}
t.into_iter().collect()
}
}
```

### **...**

```
Expand Down
18 changes: 18 additions & 0 deletions solution/2800-2899/2810.Faulty Keyboard/README_EN.md
Original file line number Diff line number Diff line change
Expand Up @@ -140,6 +140,24 @@ function finalString(s: string): string {
}
```

### **Rust**

```rust
impl Solution {
pub fn final_string(s: String) -> String {
let mut t = Vec::new();
for c in s.chars() {
if c == 'i' {
t.reverse();
} else {
t.push(c);
}
}
t.into_iter().collect()
}
}
```

### **...**

```
Expand Down
13 changes: 13 additions & 0 deletions solution/2800-2899/2810.Faulty Keyboard/Solution.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,13 @@
impl Solution {
pub fn final_string(s: String) -> String {
let mut t = Vec::new();
for c in s.chars() {
if c == 'i' {
t.reverse();
} else {
t.push(c);
}
}
t.into_iter().collect()
}
}
Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,14 @@

时间复杂度 $O(n^3)$,空间复杂度 $O(n^2)$。其中 $n$ 是数组 $nums$ 的长度。

**方法二:脑筋急转弯**

不论如何操作,最终总会剩下一个 `length == 2` 的子数组,又因为元素数值不存在负数,所以随着分割操作的进行,子数组的长度和总和都会逐渐变小,其它 `length > 2` 子数组之和肯定要比该子数组之和更大,进而,我们只需要考虑,是否存在一个 `length == 2` 且总和大于等于 `m` 的子数组即可。

> 📢 注意,当 `nums.length <= 2` 时,无需进行操作。

时间复杂度 $O(n)$,空间复杂度 $O(1)$。

<!-- tabs:start -->

### **Python3**
Expand Down Expand Up @@ -258,6 +266,40 @@ function canSplitArray(nums: number[], m: number): boolean {
}
```

```ts
function canSplitArray(nums: number[], m: number): boolean {
const n = nums.length;
if (n <= 2) {
return true;
}
for (let i = 1; i < n; i++) {
if (nums[i - 1] + nums[i] >= m) {
return true;
}
}
return false;
}
```

### **Rust**

```rust
impl Solution {
pub fn can_split_array(nums: Vec<i32>, m: i32) -> bool {
let n = nums.len();
if (n <= 2) {
return true;
}
for i in 1..n {
if nums[i - 1] + nums[i] >= m {
return true;
}
}
false
}
}
```

### **...**

```
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -217,6 +217,40 @@ function canSplitArray(nums: number[], m: number): boolean {
}
```

```ts
function canSplitArray(nums: number[], m: number): boolean {
const n = nums.length;
if (n <= 2) {
return true;
}
for (let i = 1; i < n; i++) {
if (nums[i - 1] + nums[i] >= m) {
return true;
}
}
return false;
}
```

### **Rust**

```rust
impl Solution {
pub fn can_split_array(nums: Vec<i32>, m: i32) -> bool {
let n = nums.len();
if (n <= 2) {
return true;
}
for i in 1..n {
if nums[i - 1] + nums[i] >= m {
return true;
}
}
false
}
}
```

### **...**

```
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,14 @@
impl Solution {
pub fn can_split_array(nums: Vec<i32>, m: i32) -> bool {
let n = nums.len();
if (n <= 2) {
return true;
}
for i in 1..n {
if nums[i - 1] + nums[i] >= m {
return true;
}
}
false
}
}
126 changes: 126 additions & 0 deletions solution/2800-2899/2812.Find the Safest Path in a Grid/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -494,6 +494,132 @@ function maximumSafenessFactor(grid: number[][]): number {
}
```

```ts
function maximumSafenessFactor(grid: number[][]): number {
const n = grid.length;
const g = Array.from({ length: n }, () => new Array(n).fill(-1));
const vis = Array.from({ length: n }, () => new Array(n).fill(false));
let q: [number, number][] = [];
for (let i = 0; i < n; i++) {
for (let j = 0; j < n; j++) {
if (grid[i][j] === 1) {
q.push([i, j]);
}
}
}
let level = 0;
while (q.length) {
const t: [number, number][] = [];
for (const [x, y] of q) {
if (x < 0 || y < 0 || x === n || y === n || g[x][y] !== -1) {
continue;
}
g[x][y] = level;
t.push([x + 1, y]);
t.push([x - 1, y]);
t.push([x, y + 1]);
t.push([x, y - 1]);
}
q = t;
level++;
}
const dfs = (i: number, j: number, v: number) => {
if (i < 0 || j < 0 || i === n || j === n || vis[i][j] || g[i][j] <= v) {
return false;
}
vis[i][j] = true;
return (
(i === n - 1 && j === n - 1) ||
dfs(i + 1, j, v) ||
dfs(i, j + 1, v) ||
dfs(i - 1, j, v) ||
dfs(i, j - 1, v)
);
};

let left = 0;
let right = level;
while (left < right) {
vis.forEach(v => v.fill(false));
const mid = (left + right) >>> 1;
if (dfs(0, 0, mid)) {
left = mid + 1;
} else {
right = mid;
}
}
return right;
}
```

### **Rust**

```rust
use std::collections::VecDeque;
impl Solution {
fn dfs(i: usize, j: usize, v: i32, g: &Vec<Vec<i32>>, vis: &mut Vec<Vec<bool>>) -> bool {
if vis[i][j] || g[i][j] <= v {
return false;
}
vis[i][j] = true;
let n = g.len();
i == n - 1 && j == n - 1
|| i != 0 && Self::dfs(i - 1, j, v, g, vis)
|| i != n - 1 && Self::dfs(i + 1, j, v, g, vis)
|| j != 0 && Self::dfs(i, j - 1, v, g, vis)
|| j != n - 1 && Self::dfs(i, j + 1, v, g, vis)
}

pub fn maximum_safeness_factor(grid: Vec<Vec<i32>>) -> i32 {
let n = grid.len();
let mut g = vec![vec![-1; n]; n];
let mut q = VecDeque::new();
for i in 0..n {
for j in 0..n {
if grid[i][j] == 1 {
q.push_back((i, j));
}
}
}
let mut level = 0;
while !q.is_empty() {
let m = q.len();
for _ in 0..m {
let (i, j) = q.pop_front().unwrap();
if g[i][j] != -1 {
continue;
}
g[i][j] = level;
if i != n - 1 {
q.push_back((i + 1, j));
}
if i != 0 {
q.push_back((i - 1, j));
}
if j != n - 1 {
q.push_back((i, j + 1));
}
if j != 0 {
q.push_back((i, j - 1));
}
}
level += 1;
}
let mut left = 0;
let mut right = level;
while left < right {
let mid = (left + right) >> 1;
if Self::dfs(0, 0, mid, &g, &mut vec![vec![false; n]; n]) {
left = mid + 1;
} else {
right = mid;
}
}
right
}
}
```

### **...**

```
Expand Down
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