1.4.4 统计输入中相同的数出现的次数

#include<iostream>
using namespace std;
int main()
{
  int currVal = 0; 
  int  val = 0;
  if (cin >> currVal)
  {
    int cnt = 1;
    while (cin >> val)
    {
      if (val == currVal)
      {
        ++cnt;
      }
      else
      {
        cout<< currVal << "occurs"<< cnt << "times" <<endl;
        currVal = val;
        cnt = 1;
      }
    }

    cout << currVal << "occurs" << cnt << "times" <<endl;

  }
  return 0;
}

1..5.2读取两个相同的salse_item对象输出他们的和

#include <iostream>
#include "Salse_item.h"
int main()
{
  Sales_item item1, item2;
  std::cin >> item1 >> item2;
  //首先检查item1与item2是否表示相同的书
  if (item1.isbn() == item2.isbn())
  {
    std::cout<< item1 + item2 << std::endl;
    return 0;
  }
  else
  {
    std::cerr << "Data must refer to same ISBN" << std::endl;
    return -1;
  }
}