加密.c

C 语言算法

#include<stdio.h> 
int main()
{ 
int i,j; 
char st[100]; 
printf("Please input the number as below:\n1-jia mi  2-jie mi\n");
scanf("%d",&j);
switch(j)
{
 case 1:
 printf("please input a string:\n"); 
 scanf("%s",st); 
 printf("\njia mi qian:\n%s\n",st); 
 for(i=0;st[i];i++)
 { 
 if (st[i]>='a'&& st[i]<='z') 
 st[i]-=31; 
 else if (st[i]>='A'&&st[i]<='Z') 
 st[i]+=31; 
 } 
 printf("\njia mi hou:\n%s\n",st); 
 fflush(stdin); 
 getchar(); 
 case 2:
 printf("please input a string:\n"); 
 scanf("%s",st); 
 printf("\njie mi qian:\n%s\n",st); 
 for(i=0;st[i];i++)
 { 
 if (st[i]>='a'&& st[i]<='z') 
 st[i]+=31; 
 else if (st[i]>='A'&&st[i]<='Z') 
 st[i]-=31; 
 } 
 printf("\njie mi hou:\n%s\n",st); 
 fflush(stdin); 
 getchar(); 
}
}