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feat: add solutions to lcci problems: No.01.07~01.09 #2094

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yanglbme merged 1 commit into main from dev
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168 changes: 129 additions & 39 deletions lcci/01.07.Rotate Matrix/README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,13 @@

<!-- 这里可写通用的实现逻辑 -->

原地旋转,i 的范围是 `[0, n/2)`,j 的范围是 `[i, n-1-i)`。
**方法一:原地翻转**

根据题目要求,我们实际上需要将 $matrix[i][j]$ 旋转至 $matrix[j][n - i - 1]$。

我们可以先对矩阵进行上下翻转,即 $matrix[i][j]$ 和 $matrix[n - i - 1][j]$ 进行交换,然后再对矩阵进行主对角线翻转,即 $matrix[i][j]$ 和 $matrix[j][i]$ 进行交换。这样就能将 $matrix[i][j]$ 旋转至 $matrix[j][n - i - 1]$ 了。

时间复杂度 $O(n^2),ドル其中 $n$ 是矩阵的边长。空间复杂度 $O(1)$。

<!-- tabs:start -->

Expand All @@ -62,17 +68,13 @@
```python
class Solution:
def rotate(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
n = len(matrix)
for i in range(n // 2):
for j in range(i, n - 1 - i):
t = matrix[i][j]
matrix[i][j] = matrix[n - j - 1][i]
matrix[n - j - 1][i] = matrix[n - i - 1][n - j - 1]
matrix[n - i - 1][n - j - 1] = matrix[j][n - i - 1]
matrix[j][n - i - 1] = t
for i in range(n >> 1):
for j in range(n):
matrix[i][j], matrix[n - i - 1][j] = matrix[n - i - 1][j], matrix[i][j]
for i in range(n):
for j in range(i):
matrix[i][j], matrix[j][i] = matrix[j][i], matrix[i][j]
```

### **Java**
Expand All @@ -83,19 +85,63 @@ class Solution:
class Solution {
public void rotate(int[][] matrix) {
int n = matrix.length;
for (int i = 0; i < n / 2; ++i) {
for (int j = i; j < n - 1 - i; ++j) {
for (int i = 0; i < n >> 1; ++i) {
for (int j = 0; j < n; ++j) {
int t = matrix[i][j];
matrix[i][j] = matrix[n - i - 1][j];
matrix[n - i - 1][j] = t;
}
}
for (int i = 0; i < n; ++i) {
for (int j = 0; j < i; ++j) {
int t = matrix[i][j];
matrix[i][j] = matrix[n - j - 1][i];
matrix[n - j - 1][i] = matrix[n - i - 1][n - j - 1];
matrix[n - i - 1][n - j - 1] = matrix[j][n - i - 1];
matrix[j][n - i - 1] = t;
matrix[i][j] = matrix[j][i];
matrix[j][i] = t;
}
}
}
}
```

### **C++**

```cpp
class Solution {
public:
void rotate(vector<vector<int>>& matrix) {
int n = matrix.size();
for (int i = 0; i < n >> 1; ++i) {
for (int j = 0; j < n; ++j) {
swap(matrix[i][j], matrix[n - i - 1][j]);
}
}
for (int i = 0; i < n; ++i) {
for (int j = 0; j < i; ++j) {
swap(matrix[i][j], matrix[j][i]);
}
}
}
};
```

### **Go**

```go
func rotate(matrix [][]int) {
n := len(matrix)
for i := 0; i < n>>1; i++ {
for j := 0; j < n; j++ {
matrix[i][j], matrix[n-i-1][j] = matrix[n-i-1][j], matrix[i][j]
}
}
for i := 0; i < n; i++ {
for j := 0; j < i; j++ {
matrix[i][j], matrix[j][i] = matrix[j][i], matrix[i][j]
}
}
}
```

### **JavaScript**

```js
Expand All @@ -104,34 +150,78 @@ class Solution {
* @return {void} Do not return anything, modify matrix in-place instead.
*/
var rotate = function (matrix) {
const n = matrix.length;
for (let i = 0; i < n / 2; i++) {
for (let j = i; j < n - i - 1; j++) {
let t = matrix[i][j];
matrix[i][j] = matrix[n - j - 1][i];
matrix[n - j - 1][i] = matrix[n - i - 1][n - j - 1];
matrix[n - i - 1][n - j - 1] = matrix[j][n - i - 1];
matrix[j][n - i - 1] = t;
matrix.reverse();
for (let i = 0; i < matrix.length; ++i) {
for (let j = 0; j < i; ++j) {
[matrix[i][j], matrix[j][i]] = [matrix[j][i], matrix[i][j]];
}
}
};
```

### **Go**
### **TypeScript**

```go
func rotate(matrix [][]int) {
n := len(matrix)
r, c := n/2, (n+1)/2
for i := 0; i < r; i++ {
for j := 0; j < c; j++ {
temp := matrix[i][j]
matrix[i][j] = matrix[n-j-1][i]
matrix[n-j-1][i] = matrix[n-i-1][n-j-1]
matrix[n-i-1][n-j-1] = matrix[j][n-i-1]
matrix[j][n-i-1] = temp
}
}
```ts
/**
Do not return anything, modify matrix in-place instead.
*/
function rotate(matrix: number[][]): void {
matrix.reverse();
for (let i = 0; i < matrix.length; ++i) {
for (let j = 0; j < i; ++j) {
const t = matrix[i][j];
matrix[i][j] = matrix[j][i];
matrix[j][i] = t;
}
}
}
```

### **C#**

```cs
public class Solution {
public void Rotate(int[][] matrix) {
int n = matrix.Length;
for (int i = 0; i < n >> 1; ++i) {
for (int j = 0; j < n; ++j) {
int t = matrix[i][j];
matrix[i][j] = matrix[n - i - 1][j];
matrix[n - i - 1][j] = t;
}
}
for (int i = 0; i < n; ++i) {
for (int j = 0; j < i; ++j) {
int t = matrix[i][j];
matrix[i][j] = matrix[j][i];
matrix[j][i] = t;
}
}
}
}
```

### **Rust**

```rust
impl Solution {
pub fn rotate(matrix: &mut Vec<Vec<i32>>) {
let n = matrix.len();
for i in 0..n / 2 {
for j in 0..n {
let t = matrix[i][j];
matrix[i][j] = matrix[n - i - 1][j];
matrix[n - i - 1][j] = t;
}
}
for i in 0..n {
for j in 0..i {
let t = matrix[i][j];
matrix[i][j] = matrix[j][i];
matrix[j][i] = t;
}
}
}
}
```

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