蛇形矩阵

#include <iostream>

using namespace std;

const int N = 110;

int n, m;
int q[N][N] = {0};

int main() {
    cin >> n >> m;
    //可以背过，分别表示x，y上右下左的偏移量
    int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};
    //x,y为当前坐标,d为当前的方向(上右下左0123)
    int x = 0, y = 0, d = 1;
    for (int i = 1; i <= n * m; i ++) {
        q[x][y] = i;
        int a = x + dx[d], b = y + dy[d];
        //判断是否出界或重复，如果有的话改变d的值改变方向，q[a][b] != 0说明重复
        if (a < 0 || a >= n || b < 0 || b >= m || q[a][b]) {
            d = (d + 1) % 4;
            a = x + dx[d], b = y + dy[d];
        }
        x = a, y = b; // 更新坐标
    }
    
    for (int i = 0; i < n; i ++) {
        for (int j = 0; j < m; j ++) {
            cout << q[i][j] << ‘ ‘;
        }
        cout << endl;
    }
    return 0;
}