spiral.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
	int n,s,i,j,b,t;
	cin >> n;
	int arr[n][n]{0};
	s = n*n;
	t=n;
	b = 0;
	i = j = 0;
	
	//Build the spiral
	while (true) {
		//Move right
		for (; j < n; j++) {
			if (s<=0) break;
			arr[i][j] = s--;
		}
		j--; i++;

		//Move down
		for (;i < n; i++) {
			if (s<=0) break;
			arr[i][j] = s--;	
		}
		j--;i--;
		
		//Move left
		for (;j >= b; j--) {
			if (s<=0) break;
			arr[i][j] = s--;
		}
		b++;j++;i--;

		//Move up
		for (; i >= b ; i--) {
			if (s<=0) break;
			arr[i][j] = s--;	
		}
		
		if (s<=0) break;
		n--;i++;s++;
	}

	//Print the spiral
	for (i = 0; i < t; i++) {
		for (j = 0; j < t; j++) {
			cout << setw(5) << left << arr[i][j];
		}
		cout << "\n";
	}

}