C语言：结构体struct的内存大小

#define _CRT_SECURE_NO_WARNINGS 1
#include 

struct STU1
{
	char name[20];
	int age;
	float score;
	double weight;
	float high;
};

struct BOOK
{
	char name[20];
	int price;
	char id[20];
};

int main()
{
	struct STU1 stu1;
	struct BOOK book;
	printf("%dn", sizeof(stu1)); //输出48
	printf("%dn", sizeof(book)); //输出44
	
	return 0;
}

运行结果