C/C++中memset,memcpy的使用及fill对数组的操作

/*
 Project: 数组的整体赋值与复制 
 Date: 2018/07/31
 Author: Frank Yu
 memset(数组名,0或-1,字节)
 memcpy(数组名,数组名,字节)
*/
#include<iostream>
#include<cstring> //memset需要头文件 
#include<cstdio>
#define n 5
using namespace std;
int main()
{
 int a[n];
 int b[n];
 memset(a,0,sizeof(a));//初始化为0
 //memset(b,1,sizeof(b));//初始化为1,错误 
 memset(b,-1,sizeof(b)); 
 printf("请输入%d个数:n",n);
 for(int i=0;i<n;i++)
 {
 scanf("%d",&a[i]);
 } 
 printf("第一个数组为:n");
 for(int i=0;i<n;i++)
 {
 printf("%d ",a[i]);
 } 
 printf("n");
 printf("第二个数组为:n");
 for(int i=0;i<n;i++)
 {
 printf("%d ",b[i]);
 } 
 printf("n");
 memcpy(a,b,sizeof(b));//b的元素复制给a 
 printf("第一个数组被第二个数组覆盖后:n");
 for(int i=0;i<n;i++)
 {
 printf("%d ",a[i]);
 } 
 return 0;
}

#include <iostream>
#include <string.h>
using namespace std;
struct SomeInfo
{
 char id[30];
 char name[30];
};
 
struct TotalInfo
{
 char total[20];
 SomeInfo my[10];
};
 
class myClass
{
 public:
 myClass()
 {
 }
 
 ~myClass()
 {
 } 
 
 void memcopy(int ,TotalInfo);
 void print();
 private:
 TotalInfo m_totalInfo;
 int m_count;
}; 
 
void myClass::memcopy(int count ,TotalInfo info)
{
 m_count = count;
 memcpy(&m_totalInfo,&info,sizeof(m_totalInfo));
}
void myClass::print()
{
 std::cout << m_totalInfo.total << std::endl;
 for (int i = 0; i != m_count ; ++i)
 {
 std::cout << m_totalInfo.my[i].id << std::endl;
 std::cout << m_totalInfo.my[i].name << std::endl;
 }
}
int main()
{
 myClass here = myClass();
 TotalInfo totalInfo;
 memset(&totalInfo, 0, sizeof(totalInfo));
 char total[20] = "totalInfo.total"; 
 memcpy(totalInfo.total,total,20); 
 int count = 5;
 for (int i = 0; i != count ; ++i)
 {
 char _id[30] = "totalInfo.Some.id";
 char _name[30] = "totalInfo.Some.name";
 memcpy(totalInfo.my[i].id, _id,sizeof(_id));
 memcpy(totalInfo.my[i].name, _name,sizeof(_name));
 }
 here.memcopy(count, totalInfo);
 here.print();
 return 0;
}