求1！+2！+3！……+N!

#include<stdio.h>
#define N 3
//求1！+2！+3！……+N!
int main()
{
	int sum = 0;	
	for (int j = 1; j < N+1; j++)
	{
		int ret = 1;
		for (int i = 1; i < j+1; i++)
		{
			ret *= i;			
		}
		sum += ret;
	}
	printf("%d\n", sum);
	return 0;
}