#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define key 3
#define MAX 100
void encryption(char a[])
{
int i;
for (i = 0; i < strlen(a); i++)
{
if (a[i] >= 'a' && a[i] <= 'w')
a[i] = a[i] - 29;
else if (a[i] >='x'&&a[i]<='z')
a[i] = a[i]-120+65;
}
printf("加密结果为%s\n", a);
}
void decryption(char a[])
{
int i;
for (i = 0; i < strlen(a); i++)
{
if (a[i] >= 'D' && a[i] <= 'Z')
a[i] = a[i] + 29;
else if (a[i] >= 'A' && a[i] <= 'C')
a[i] =a[i] -65 + 120;
}
printf("解密结果为%s\n", a);
}
int main()
{
printf("密钥可在源代码开头更改\n");
char plaintext[MAX], ciphertext[MAX];
printf("请输入小写明文以加密:");
gets_s(plaintext);
plaintext[strlen(plaintext)] = '\0';
encryption(plaintext);
printf("请输入大写密文以解密");
gets_s(ciphertext);
ciphertext[strlen(ciphertext)] = '\0';
decryption(ciphertext);
return 0;
}
05-07
972

05-15
05-15
05-15