#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#define UP 0
#define RIGHT 1
#define DOWN 2
#define LEFT 3

int main() {
    int moves[4] = {0, 1, 0, -1};
    int *arr;
    int size = 5;
    int direction = RIGHT;
    int index = 0;
    scanf("%d", &size);
    arr = (int*)calloc(size * size, sizeof(int));
    moves[UP] = -size;
    moves[DOWN] = size;

    for (int i = 1; i <= size * size; i++) {
        if (index == size - 1 || index == size * size - 1 || index == size * (size - 1) || arr[index + moves[direction]] != 0)
            direction = (direction + 1) % 4;
        arr[index] = i;
        index += moves[direction];
    }
    for (int i = 0; i < size * size; i++) {
        printf("%3d ", arr[i]);
        if (!((i + 1) % size))
            printf("\n");
    }
}

딱히 최대한으로 일반화하는게 좋지만은 않은거같아...