全排列的递归实现

#include
#include

void fun(int cur[], int m, int arr[], int n) {
	int i, j;
	if (n == 0) {
		for (i = 0; i < m; i++) {
			printf("%d ", cur[i]);
		}
		printf("\n");
	}

	for (i = 0; i < n; i++) {
		cur[m] = arr[i];
		int* new_arr = (int*)malloc(sizeof(int) * (n - 1));
		for (j = 0; j < n - 1; j++) {
			if (j < i)new_arr[j] = arr[j];
			else new_arr[j] = arr[j + 1];
		}
		fun(cur, m + 1, new_arr, n - 1);
		free(new_arr);
	}	
}

int main() {
	int n, i, cur[MAX] = { 0 }, arr[MAX];
	scanf("%d", &n);

	for (i = 0; i < MAX; i++) {
		arr[i] = i + 1;
	}

	fun(cur, 0, arr, n);

	return 0;
}