题解 | #回型矩阵#

知识点：

复合类型：

二维数组。

#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    int arr[20][20] = {0};
    int up = 0, left = 0, right = n - 1, down = n - 1;
    int x = 1;

    while (x <= n * n) {
        for (int i = left; i <= right; i++) {
            arr[up][i] = x++;
        }
        up++;

        for (int i = up; i <= down; i++) {
            arr[i][right] = x++;
        }
        right--;

        for (int i = right; i >= left; i--) {
            arr[down][i] = x++;
        }
        down--;

        for (int i = down; i >= up; i--) {
            arr[i][left] = x++;
        }
        left++;
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cout << arr[i][j] << " ";
        }
        putchar('\n');
    }
    putchar('\n');

    return 0;
}