题目描述

blablabla

核心想法

1. 最外层输出一圈1
2. 递归输出中间部分
3. 中间部分还要加1

C++ 代码

#include <iostream>

using namespace std;
const int N = 110;

void aux(int A[][N], int n, int level) {
    if (n == 0) {
        return;
    }
    if (n == 1) {
        A[level][level] = 1;
        return ;
    }
    // 最外层套一层1
    for (int i = level; i != n + level; ++i) {
        for (int j = level; j != n + level; ++j) {
            if (i == level || i == n - 1 + level || j == level || j == n - 1 + level);
                A[i][j] = 1;
        }   
    }
    // 递归填充中间部分
    aux(A, n - 2, level + 1);

    // 中间部分加1
    for (int i = level + 1; i != n - 1 + level; ++i) {
        for (int j = level + 1; j != n - 1 + level; ++j) {
                A[i][j] += 1;
        }   
    }
}

int main() {
    int A[N][N];

    int n;
    while (cin >> n && n != 0) {
        // 递归生成回形数组
        aux(A, n, 0);

        // 打印数组
        for (int i = 0; i != n; ++i) {
            for (int j = 0; j != n; ++j) {
                cout << A[i][j] << " ";
            }
            cout << endl;
        }
        cout << endl;
    }
}