#include <iostream> using namespace std; #define STR_LEN 80 #define MAX_LINE 20 //读入一行，长度不超过maxLength void readLine(char str[], int maxLength) { int i = 0; while (i < maxLength) { char ch = cin.get(); if (ch != '\n') { str[i] = ch; } else { break; } i++; } str[i] = '\0'; } void caesarEncrypt(char plainText[][STR_LEN + 1], char cipherText[][STR_LEN + 1], int key) { int a = 0; while (cipherText[a][0] != '#') { a = a + 1; } for (int j = 0; j < a; j++) { int i = 0; while (cipherText[j][i] != '\0') { if (isalpha(cipherText[j][i])) { plainText[j][i] = ((cipherText[j][i] + key - 'A') % 26) + 'A'; } else { plainText[j][i] = cipherText[j][i]; } i++; } } } int main() { char cipherText[MAX_LINE][STR_LEN + 1]; //存储密文 char plainText[MAX_LINE][STR_LEN + 1]; int key; //输入明文 readLine(cipherText[0], STR_LEN); //输入密钥 cin >> key; //按密钥进行恺撒加密 caesarEncrypt(plainText, cipherText, key); //输出密文 for (int i = 0; i < MAX_LINE; i++) { for(int j=0 ; j<STR_LEN; j++) { if (plainText[i][0] == '\0') { break; } cout << plainText[j][i]; } } return 0; }这个代码哪里有问题

这份代码有几个问题：

1.在`caesarEncrypt`函数中，应该将密文的内容赋给明文而不是将明文的内容赋给密文。

2.在输出密文时，应该按照行列的顺序输出，而不是按列行的顺序输出。

3.在输出密文时，应该判断明文是否为空，如果为空就跳出循环，否则会输出一些奇怪的字符。

下面是修改后的代码：

#include <iostream> 
using namespace std;  

#define STR_LEN 80 
#define MAX_LINE 20  

//读入一行，长度不超过maxLength 
void readLine(char str[], int maxLength) {     
    int i = 0;     
    while (i < maxLength) {         
        char ch = cin.get();         
        if (ch != '\n') {             
            str[i] = ch;         
        } else {             
            break;         
        }         
        i++;     
    }     
    str[i] = '\0'; 
}  

void caesarEncrypt(char plainText[][STR_LEN + 1], char cipherText[][STR_LEN + 1], int key) {     
    int a = 0;     
    while (cipherText[a][0] != '#') {         
        a = a + 1;     
    }     
    for (int j = 0; j < a; j++) {         
        int i = 0;         
        while (cipherText[j][i] != '\0') {             
            if (isalpha(cipherText[j][i])) {                 
                plainText[j][i] = ((cipherText[j][i] - 'A' + key) % 26) + 'A';             
            } else {                 
                plainText[j][i] = cipherText[j][i];             
            }             
            i++;         
        }         
        plainText[j][i] = '\0';     
    } 
}  

int main() {     
    char cipherText[MAX_LINE][STR_LEN + 1]; //存储密文     
    char plainText[MAX_LINE][STR_LEN + 1];      
    int key;     
    //输入密文     
    for (int i = 0; i < MAX_LINE; i++) {         
        readLine(cipherText[i], STR_LEN);         
        if (cipherText[i][0] == '#') {             
            break;         
        }     
    }     
    //输入密钥     
    cin >> key;     
    //按密钥进行恺撒加密     
    caesarEncrypt(plainText, cipherText, key);     
    //输出密文     
    for (int i = 0; i < MAX_LINE; i++) {         
        if (plainText[i][0] == '\0') {             
            break;         
        }         
        for (int j = 0; plainText[i][j] != '\0'; j++) {             
            cout << plainText[i][j];         
        }         
        cout << endl;     
    }     
    return 0; 
}