Question

一行电文按下规律译成密码 A-Z，a-z，B-Y,b-y，C-X,c-x.....第i字母变成（26-i+1）个字母已知密码Umtorhs

求编程将密码译成原文
c语言编程

Answer 1

char str[7],string[7];
gets(str);
for(int i=0;i<7&&str[i]!='\0';i++){
if(str[i]>='A'&&str[i]<='Z') {
string[i] = str[i] - 26 + 2 * (91 - str[i]) - 1;
}else if(str[i]>='a'&&str[i]<='z'){
string[i]=str[i] - 26 + 2 * (122 - str[i]) - 1;
}
}
for(int i=0;i<7;i++){
printf("%c",string[i]);
}

Answer 2

#include <stdio.h>
#include <string.h>
void main ()
{
int i;
char x[10],y[10];
char c;
gets(x);
for (i=0;x[i]!='\0';i++)
{
if (x[i]>='A'&&x[i]<='Z')
y[i]=64+(26-(x[i]-64));
else if (x[i]>='a'&&x[i]<='z')
y[i]=96+(27-(x[i]-96));
else
y[i]=x[i];
}
y[i]='\0';
puts(y);
}