歐維斯福利設

#include <iostream>
#include <stdlib.h>
using namespace std;
int main()
{
    cout<<"Hello World!"<<endl;
    system("pause");
    return 0;
}

/*編譯成test.exe後，假設存放在:
D:\cpp files\test
打開命令提示字元(按下win + R，打cmd)，輸入:
D:\cpp files\test\test.exe 87
*/
#include <iostream>
using namespace std;
int main(int argc,char *argv[])
{
  int i;
  cout<<"argc = "<<argc<<endl;
  for(i=0;i<argc;i++)
    cout<<argv[i]<<endl;
  return 0;
}

#include <iostream>
#include <cstdlib>
#include <ctime>
#define SIZE 20
using namespace std;
int search(int [ ],int,int,int);
int main(void)
{
    int i,a[SIZE],from=0,key;
    srand(time(NULL));  //亂數產生陣列元素值
    for(i=0;i<SIZE;i++)
      a[i] = rand( ) % 10 + 1;  
    cout<<"請輸入欲搜尋的值(1~10)";
    cin>>key;
    while(from < SIZE) {
      int ans;
      ans = search(a,from,SIZE,key);
      if(ans == -1) {
        if(!from)    
          cout<<key<<" not found\n";
        break;
      } else {
            cout<<key<<" found at a["<<ans<<"] = "<<a[ans]<<endl;
            from = ans + 1;
      }
    }
    return 0;
}
int search(int a[ ],int from,int size,int key)
{
   int i;
   for(i=from;i<size;i++)
     if(a[i] == key)
       return i;
   return -1;      
}

#include <iostream>
using namespace std;
void vset(int,int);
void rset(int*,int);
int main(void)
{
  int x=0,*p;           //宣告變數x及整數指標p
  p = &x;             //取得變數x的位址（將p指向x）
  vset(x,1);            
  cout<<"x = "<<x;
  rset(p,1);            //將指標當作引數來傳遞進函式
  cout<<"x = "<<x;
  return 0;
}
void vset(int x,int y)
{
  x = y;
}
void rset(int *p,int y)
{
  *p = y;              //間接存取變數x
}

#include <iostream>
using namespace std;
int Mystrcmp(char *,char *);
int main(void)
{
  int result;
  char word1[ ] = "I like C";    //字串1
  char word2[ ] = "This is fun";  //字串2
  result = Mystrcmp(word1,word2);
  if(!result)
    cout<<"word1 equal word2\n";
  else
    cout<<"word1 does not equal word2\n";
  return 0;
}
int Mystrcmp(char *str1,char *str2)
{
  int i;
  for(i=0;!(*(str1+i) == '\0' && *(str2+i) == '\0'); i++)
    if(*(str1+i) != *(str2+i)) return -1;
  return 0;
}

#include <iostream>
using namespace std;
void Mystrcpy(char *,char *);
int main(void)
{
  int result;
  char word1[ ] = "I like C";
  char word2[ ] = "This is fun";
  Mystrcpy(word1,word2);
  cout<<"word2 = "<<word2<<endl;
  return 0;
}
void Mystrcpy(char *str1,char *str2)
{
  int i;
  for(i=0;*(str1+i)!='\0';i++)
  *(str2+i) = *(str1+i);
  *(str2 + i) = '\0';
}

#include <iostream>
#include <fstream>
using namespace std;
char* encode(char*);
char* decode(char*);
int main(void)
{
  char ch,str[80];
  cout<<"請輸入字串:";
  gets(str);
  cout<<"您要 1)加密 2)解密 :";
  cin>>ch;
  if(ch == '1') {
    cout<<"After encode : ";
    cout<<encode(str);
  } else if (ch == '2') {
    cout<<"After decode :";
    cout<<decode(str);
  } else
    cout<<"Unknown input";
  return 0;
}
char* encode(char *str)
{
      char *r=str;
      while(*str) {
        *str = *str + 13;
        str++;
      }  
      return r;
}
char* decode(char *str)
{
      char *r=str;
      while(*str) {
        *str = *str - 13;
        str++;
      }
      return r;
}