완전순열 더블릿

#include <stdio.h>
 
int dp[1000] = { 0 };
 
int main() {
    int n;
    scanf("%d", &n);
 
    dp[2] = 1;
    for (int i = 3; i <= n; i++) {
        dp[i] = (dp[i - 1] + dp[i - 2])*(i - 1);
    }
    printf("%d", dp[n]);
}