class()的妙用

计数特定商品销售记录

最新推荐文章于 2025-10-05 11:12:57 发布

原创最新推荐文章于 2025-10-05 11:12:57 发布 · 433 阅读

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#class #string #algorithm #soap #vector

#pragma warning(disable:4786)
#include <iostream.h>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
const string ToothbrushCode("0003");
class IsAToothbrush
{public:
bool operator() ( string& SalesRecord )
{return SalesRecord.substr(0,4)==ToothbrushCode;}
};
void main (void)
{
  vector<string> SalesRecords;
  SalesRecords.push_back("0001 Soap");
  SalesRecords.push_back("0002 Shampoo");
  SalesRecords.push_back("0003 Toothbrush");
  SalesRecords.push_back("0004 Toothpaste");
  SalesRecords.push_back("0003 Toothbrush");
int NumberOfToothbrushes(0);
  NumberOfToothbrushes = count_if (SalesRecords.begin(), SalesRecords.end(),IsAToothbrush());
  cout << "There were " << NumberOfToothbrushes << " toothbrushes sold" << endl;
}

结果:
There were 2 toothbrushes sold
__________________________________________________________________

#pragma warning(disable:4786)
#include <iostream.h>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
class IsAToothbrush
{
public:
IsAToothbrush(string& InToothbrushCode) : ToothbrushCode(InToothbrushCode) {}
bool operator() (string& SalesRecord)
{ return SalesRecord.substr(0,4)==ToothbrushCode; }
private:
string ToothbrushCode;
};
void main (void)
{
vector<string> SalesRecords;
SalesRecords.push_back("0001 Soap");
SalesRecords.push_back("0002 Shampoo");
SalesRecords.push_back("0003 Toothbrush");
SalesRecords.push_back("0004 Toothpaste");
SalesRecords.push_back("0003 Toothbrush");
string VariableToothbrushCode("0003");
int NumberOfToothbrushes(0);
NumberOfToothbrushes = count_if (SalesRecords.begin(), SalesRecords.end(),
IsAToothbrush(VariableToothbrushCode));
cout << "There were  " << NumberOfToothbrushes << " toothbrushes matching code "<< "0003" << " sold" << endl;
}

结果:
There were  2 toothbrushes matching code 0003 sold