Spiral Matrix II

class Solution {
public:
    vector<vector<int>> generateMatrix(int n) {
        vector<vector<int>> a(n, vector<int>(n, 0));
        int top = 0, bottom = n - 1, left = 0, right = n - 1, v = 1;
        while (top <= bottom && left <= right) {
            for (int j = left; j <= right; ++j) a[top][j] = v++;
            ++top;
            for (int i = top; i <= bottom; ++i) a[i][right] = v++;
            --right;
            if (top <= bottom) {
                for (int j = right; j >= left; --j) a[bottom][j] = v++;
                --bottom;
            }
            if (left <= right) {
                for (int i = bottom; i >= top; --i) a[i][left] = v++;
                ++left;
            }
        }
        return a;
    }
};

func generateMatrix(n int) [][]int {
    a := make([][]int, n)
    for i := range a {
        a[i] = make([]int, n)
    }
    top, bottom, left, right, v := 0, n-1, 0, n-1, 1
    for top <= bottom && left <= right {
        for j := left; j <= right; j++ {
            a[top][j] = v
            v++
        }
        top++
        for i := top; i <= bottom; i++ {
            a[i][right] = v
            v++
        }
        right--
        if top <= bottom {
            for j := right; j >= left; j-- {
                a[bottom][j] = v
                v++
            }
            bottom--
        }
        if left <= right {
            for i := bottom; i >= top; i-- {
                a[i][left] = v
                v++
            }
            left++
        }
    }
    return a
}

from typing import List

class Solution:
    def generateMatrix(self, n: int) -> List[List[int]]:
        a = [[0] * n for _ in range(n)]
        top, bottom, left, right, v = 0, n - 1, 0, n - 1, 1
        while top <= bottom and left <= right:
            for j in range(left, right + 1):
                a[top][j] = v
                v += 1
            top += 1
            for i in range(top, bottom + 1):
                a[i][right] = v
                v += 1
            right -= 1
            if top <= bottom:
                for j in range(right, left - 1, -1):
                    a[bottom][j] = v
                    v += 1
                bottom -= 1
            if left <= right:
                for i in range(bottom, top - 1, -1):
                    a[i][left] = v
                    v += 1
                left += 1
        return a

function generateMatrix(n) {
    const a = Array.from({ length: n }, () => new Array(n).fill(0));
    let top = 0, bottom = n - 1, left = 0, right = n - 1, v = 1;
    while (top <= bottom && left <= right) {
        for (let j = left; j <= right; j++) a[top][j] = v++;
        top++;
        for (let i = top; i <= bottom; i++) a[i][right] = v++;
        right--;
        if (top <= bottom) {
            for (let j = right; j >= left; j--) a[bottom][j] = v++;
            bottom--;
        }
        if (left <= right) {
            for (let i = bottom; i >= top; i--) a[i][left] = v++;
            left++;
        }
    }
    return a;
}

class Solution {
    public int[][] generateMatrix(int n) {
        int[][] a = new int[n][n];
        int top = 0, bottom = n - 1, left = 0, right = n - 1, v = 1;
        while (top <= bottom && left <= right) {
            for (int j = left; j <= right; j++) a[top][j] = v++;
            top++;
            for (int i = top; i <= bottom; i++) a[i][right] = v++;
            right--;
            if (top <= bottom) {
                for (int j = right; j >= left; j--) a[bottom][j] = v++;
                bottom--;
            }
            if (left <= right) {
                for (int i = bottom; i >= top; i--) a[i][left] = v++;
                left++;
            }
        }
        return a;
    }
}

function generateMatrix(n: number): number[][] {
    const a: number[][] = Array.from({ length: n }, () => new Array(n).fill(0));
    let top = 0, bottom = n - 1, left = 0, right = n - 1, v = 1;
    while (top <= bottom && left <= right) {
        for (let j = left; j <= right; j++) a[top][j] = v++;
        top++;
        for (let i = top; i <= bottom; i++) a[i][right] = v++;
        right--;
        if (top <= bottom) {
            for (let j = right; j >= left; j--) a[bottom][j] = v++;
            bottom--;
        }
        if (left <= right) {
            for (let i = bottom; i >= top; i--) a[i][left] = v++;
            left++;
        }
    }
    return a;
}