题解 | #字符串加解密#

#include <stdio.h>
#include <string.h>
#define diff 32
#define gap 25

//加密
void encrypt(char str[]) {

    for (int i = 0; i < strlen(str); i++) {
        //变换大小写
        if (str[i] >= 'A' && str[i] <= 'Z') {
            if (str[i] == 'Z') {
                str[i] = 'a';
            } else {
                str[i] = str[i] + diff + 1;
            }
            continue;
        }
        if (str[i] >= 'a' && str[i] <= 'z') {
            if (str[i] == 'z') {
                str[i] = 'A';
            } else {
                str[i] = str[i] - diff + 1;
            }
            continue;
        }

        //处理数字
        if (str[i] >= '0' && str[i] <= '9') {
            if (str[i] == '9') {
                str[i] = '0';
            } else {
                str[i] = str[i] + 1;
            }
            continue;
        }
    }



}

//解密
void decode(char str[]) {

    for (int i = 0; i < strlen(str); i++) {
        //大写变小写
        if (str[i] >= 'A' && str[i] <= 'Z') {
            if (str[i] == 'A') {
                str[i] = 'z';
            } else {
                str[i] = str[i] + diff - 1;
            }
            continue;
        }

        if (str[i] >= 'a' && str[i] <= 'z') {
            if (str[i] == 'a') {
                str[i] = 'Z';
            } else {
                str[i] = str[i] - diff - 1;
            }
            continue;
        }

        //处理数字
        if (str[i] >= '0' && str[i] <= '9') {
            if (str[i] == '0') {
                str[i] = '9';
            } else {
                str[i] = str[i] - 1;
            }
            continue;
        }
    }

}

int main() {
    char encrypt_str[1002] = {0};
    char decode_str[1002] = {0};

    scanf("%s %s", encrypt_str, decode_str);

    encrypt(encrypt_str);

    decode(decode_str);

    printf("%s\n%s",encrypt_str,decode_str);
    return 0;
}