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

YangFong · web-flow · commit 493eb33f5b83 · 2023-08-20T12:58:16.000+08:00
- No.2810.Faulty Keyboard
- No.2811.Check if it is Possible to Split Array
- No.2812.Find the Safest Path in a Grid
diff --git a/solution/2800-2899/2810.Faulty Keyboard/README.md b/solution/2800-2899/2810.Faulty Keyboard/README.md
@@ -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()
+    }
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/2800-2899/2810.Faulty Keyboard/README_EN.md b/solution/2800-2899/2810.Faulty Keyboard/README_EN.md
@@ -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()
+    }
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/2800-2899/2810.Faulty Keyboard/Solution.rs b/solution/2800-2899/2810.Faulty Keyboard/Solution.rs
@@ -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()
+    }
+}
diff --git a/solution/2800-2899/2811.Check if it is Possible to Split Array/README.md b/solution/2800-2899/2811.Check if it is Possible to Split Array/README.md
@@ -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**
@@ -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
+    }
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/2800-2899/2811.Check if it is Possible to Split Array/README_EN.md b/solution/2800-2899/2811.Check if it is Possible to Split Array/README_EN.md
@@ -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
+    }
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/2800-2899/2811.Check if it is Possible to Split Array/Solution.rs b/solution/2800-2899/2811.Check if it is Possible to Split Array/Solution.rs
@@ -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
+    }
+}
diff --git a/solution/2800-2899/2812.Find the Safest Path in a Grid/README.md b/solution/2800-2899/2812.Find the Safest Path in a Grid/README.md
@@ -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
+    }
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/2800-2899/2812.Find the Safest Path in a Grid/README_EN.md b/solution/2800-2899/2812.Find the Safest Path in a Grid/README_EN.md
diff --git a/solution/2800-2899/2812.Find the Safest Path in a Grid/Solution.rs b/solution/2800-2899/2812.Find the Safest Path in a Grid/Solution.rs
