C++ 实验一

2-28：

#include <iostream>
using namespace std;
int name()
{
 char n;
 cout << "Menu:A(dd) D(elete) S(ort) Q(uit),Select one:" << endl;
 cin >> ;
 while (n != 'Q')
 {
  switch (n)
  {
  case'A':
  {
   cout << "The date has been added" << endl; break;
  }
  case'D':
  {
   cout << "The data has been deleted" << endl; break;
  }
  case'S':
  {
   cout << "The data has been sorted" << endl; break;
  }
  }
  cin >> n;
 }
 system("pause");
 return 0;
}

 

#include<iostream>
using namespace std;
int main()
{
 char n;
 cout << "Menu:A(dd) D(elete) S(ort) Q(uit),Selectone :" << endl;
 cin >> n;
 while (n != 'Q')
 {
  if (n == 'A')
  {
   cout << "The data has been added" << endl;
  }
  if (n == 'D')
  {
   cout << "The data has been deleted" << endl;
  }
  if (n == 'S')
  {
   cout << "The data has been sorted" << endl;
  }
  cin >> n;
 }
 system("pause");
 return 0;
}

 

 2-29：

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
 int i, j, k, flag;
 i = 2;
 while (i <= 100)
 {
  flag = 1;
  int k = (int)sqrt((float)i);
  j = 2;
  while (j <= k)
  {
   if (i%j == 0)
   {
    flag = 0; break;
   }
   j++;
  }
  if (flag)
   cout << i << "为质数。" << endl;
  i++;
 }
 system("pause");
 return 0;
}

 

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
 int i, j, k, flag;
 i = 2;
 do {
  flag = 1;
  int k = (int)sqrt((float)i);
  j = 2;
  do {
   if (i%j == 0)
   {
    flag = 0; break;
   }
   j++;
  } while (j <= k);
  if (flag)
   cout << i << "为质数。" << endl;
  i++;
 } while (i <= 100);
  system("pause");
  return 0;
}

 

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
 int i, j, k, flag;
 for (i = 2; i <= 100; i++)
 {
  flag = 1;
  int k = (int)sqrt((float)i);
  for (j = 2; j <= k; j++)
  {
   if (i%j == 0)
   {
    flag = 0; break;
   }
  }
  if (flag)
   cout << i << "为质数。" << endl;
 }
 system("pause");
}

2-32：

#include<iostream>
#include<stdlib.h>
#include<time.h>
using namespace std;
int main()
{
 int x;
    srand(time(0));
    int number = rand() % 100 + 1;
    cout << "猜这个数: ";
    cin >> x;
 while (1)
 {
  if (x != number)
  {
   if (x < number)
   {
    cout << "小" << endl;
   }
   else
   {
    cout << "大" << endl;
   }
  }
  else
  {
   cout << "正确" << endl; break;
  }
  cin >> x;
 }
 system("pause");
 return 0;
}

 

 

#include<iostream>
#include<stdlib.h>
#include<time.h>
using namespace std;
int main()
{
 int x;
    srand(time(0));
    int number = rand() % 100 + 1;
    cout << "猜这个数: ";
    cin >> x;
 do
 {
  if (x != number)
  {
   if (x < number)
   {
    cout << "小" << endl;
   }
   else
   {
    cout << "大" << endl;
   }
  }
  else
  {
   cout << "正确" << endl; break;
  }
  cin >> x;
 } while (1);
 system("pause");
 return 0;
}

2-34:

#include<iostream>
#include<iomanip>
using namespace std;
void ball(int a)
{
 switch (a)
 {
 case 1:cout << "red "; break;
 case 2:cout << "yellow "; break;
 case 3:cout << "blue "; break;
 case 4:cout << "white "; break;
 case 5:cout << "black "; break;
 }
}
int main()
{
 int i, j, k, n = 0;
 for (i = 1; i <= 5; i++)
 {
  for (j = i + 1; j <= 5; j++)
  {
   for (k = j + 1; k <= 5; k++)
   {
    ball(i);
    ball(j);
    ball(k);
    cout << endl;
    n++;
   }
  }
 }
 cout << "number：" << n << endl;
 system("pause");
 return 0;
}