大块头加密

//替换密码
#include <stdio.h>
#include <string.h>
#include <iostream.h>
void main()
{ char str[12]="how are you";
cout<<str<<endl;
int i;
for(i=0;i<=11;i++)
{str[i]+=4;
cout<<str[i];}
cout<<endl;}

//换位密码
#include <iostream.h>
#include <stdio.h>
#include <string.h>
void main()
{char str[12]="how are you";
int i,j;
char p;
printf("%s\n",str);
for(i=0,j=1;i<=10,j<=11;)
{p=str[i];
str[i]=str[j];
str[j]=p;
cout<<str[i]<<str[j];
i+=2;
j+=2;}
cout<<endl;}

额？
这是什么方法啊？