C 解法, 执行用时: 1ms, 内存消耗: 276KB, 提交时间: 2020-10-15

#include <stdio.h>
#include <ctype.h>

int main(void){
    const int sz = 128;
    char ENC[128];
    char DEC[128];
    char enc[sz], dec[sz];
    char *p;
    int i;
    ENC['9'] = '0';
    ENC['Z'] = 'a';
    ENC['z'] = 'A';
    for(i = 0; i < sz; ++i){
        if(i == '9' || i == 'z' || i == 'Z') continue;
        else if(isdigit(i))
            ENC[i] = i + 1;
        else if(islower(i))
            ENC[i] = toupper(i + 1);
        else if(isupper(i))
            ENC[i] = tolower(i + 1);
        else ENC[i] = i;
    }
    DEC['0'] = '9';
    DEC['A'] = 'z';
    DEC['a'] = 'Z';
    for(i = 0; i < sz; ++i){
        if(i == '0' || i == 'A' || i == 'a') continue;
        if(isdigit(i))
            DEC[i] = i - 1;
        else if(islower(i))
            DEC[i] = toupper(i - 1);
        else if(isupper(i))
            DEC[i] = tolower(i - 1);
        else DEC[i] = i;
    }
    while(scanf("%s\n%s\n", enc, dec) == 2){
        for(p = enc; *p; ++p) *p = ENC[*p];
        for(p = dec; *p; ++p) *p = DEC[*p];
        printf("%s\n%s\n", enc, dec);
    }
}

C 解法, 执行用时: 1ms, 内存消耗: 304KB, 提交时间: 2021-08-31

#include<stdio.h>
#include<string.h>
int main()
{
	void Encrypt(char aucPassword[], char aucResult[]);
	void unEncrypt(char result[], char password[]);
    char password1[101]={},result2[101] = {};
    while(gets(password1))
	{
        gets(result2);
        char password2[101]={},result1[101] = {};
        Encrypt(password1,result1);
        unEncrypt(result2,password2);
    }
    return 0;
}
 
void Encrypt(char aucPassword[], char aucResult[])
{
    int i;
    for(i=0;aucPassword[i]!='\0';i++)
    {
    	if(aucPassword[i]>='a'&&aucPassword[i]<='y')
    	{
        	aucResult[i] = aucPassword[i]-31;
    	}
    	else if(aucPassword[i]=='z')
    	{
			aucResult[i] = 'A';
    	}
    	else if(aucPassword[i]>='A'&&aucPassword[i]<='Y')
    	{
        	aucResult[i] = aucPassword[i]+33;
    	}
    	else if(aucPassword[i]=='Z')
    	{
        	aucResult[i] = 'a';
    	}
    	else if(aucPassword[i]>='0'&&aucPassword[i]<='8')
    	{
        	aucResult[i] = aucPassword[i]+1;
    	}
    	else if(aucPassword[i]=='9')
    	{
    		aucResult[i] = '0';	
		}   
    	else 
		{
			aucResult[i] = aucPassword[i];
		}
	}
    puts(aucResult);
}
 
void unEncrypt(char result[], char password[])
{
    int i;
    for(i=0;result[i]!='\0';i++)
    {
    	if(result[i]>='b'&&result[i]<='z')
    	{
    		password[i] = result[i]-33;
		}
        
    	else if(result[i]=='a')
    	{
    		password[i] = 'Z';
		}
        else if(result[i]>='B'&&result[i]<='Z')
        {
        	password[i] = result[i]+31;
		}  
    	else if(result[i]=='A')
    	{
    		password[i] = 'z';
		}
    	else if(result[i]>='1'&&result[i]<='9')
    	{
    		password[i] = result[i]-1;
		}
    	else if(result[i]=='0')
    	{
    		password[i] = '9';
		}
        else 
        {
        	password[i] = result[i];
		}	
    }
    puts(password);
}