Zigzag scan

#include<bits/stdc++.h>

using namespace std;

const int N = 5500;

int a[N][N];
int visited[N][N];

int dx[4] = {
    0, 1, 1, -1};
int dy[4] = {
    1, -1, 0, 1};

int result[260000];

int main() {
    
	int n;
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) {
    
		for (int j = 1; j <= n; j++) {
    
			scanf("%d", &a[i][j]);
			visited[i][j] = 0;
		}
	}
	int i = 1, j = 1;
	int cunt = 1;
	result[cunt] = a[i][j];
	int k = 4;
	int sum = 0;
	visited[1][1] = 1;
	while (cunt < n * n) {
    
		//printf("*********\n");
		if (i + dx[k % 4] >= 1 && j + dy[k % 4] >= 1 && i + dx[k % 4] <= n && j + dy[k % 4] <= n && !visited[i + dx[k % 4]][j + dy[k % 4]]) {
    
			i = i + dx[k % 4];
			j = j + dy[k % 4];
			visited[i][j] = 1;
			if (k % 4 == 0 || k % 4 == 2) k++;
			cunt++;
			result[cunt] = a[i][j];
			//printf("%d %d %d\n",i,j,cunt);
		} else {
    
			k++;
		}

	}
	for (int i = 1; i <= cunt; i++) {
    
		printf("%d ", result[i]);
	}
	return 0;
}