spiral.cpp

#include <bits/stdc++.h>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n;
    cin >> n;
    vector<vector<int>> m(n, vector<int>(n, 0));
    m[0][0] = 1;

    int x = 0, y = 1;
    string dir = "down";
    while (m[y][x] == 0) {
        if (dir == "down") {
            m[y][x] = m[y-1][x] + 1;
            if (y == n - 1 or m[y+1][x] != 0) {
                x++;
                dir = "right";
            }
            else y++;
        }
        else if (dir == "right") {
            m[y][x] = m[y][x-1] + 1;
            if (x == n - 1 or m[y][x+1] != 0) {
                y--;
                dir = "up";
            }
            else x++;
        }
        else if (dir == "up") {
            m[y][x] = m[y+1][x] + 1;
            if (y == 0 or m[y-1][x] != 0) {
                x--;
                dir = "left";
            }
            else y--;
        }
        else {
            m[y][x] = m[y][x+1] + 1;
            if (x == 0 or m[y][x-1] != 0) {
                y++;
                dir = "down";
            }
            else x--;
        }
    }

    for (auto &x : m) {
        for (auto &y : x) cout << y << " ";
        cout << endl;
    }
}