检查重复的字符没有给我想要的输出

Question

我正在尝试使用我编写的以下代码首先检查字符串 argv[1] 中是否重复了字母表中的任何字符，无论它是大写还是小写。即使我用不包含重复字符的命令行参数输入它，它也会不断吐出我有重复的结果。

#include <cs50.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>




int main (int argc, string argv[])
{
    //checking to make sure only one command line argument can be inputted
    if (argc != 2)
    {
        printf("Usage: ./caesar key\n");
        return 1;
    }

    //defining key argument and making sure string is a certain length
    int key = strlen(argv[1]);

    if (key != 26)
    {
        printf("key is not long enough\n");
        return 1;
    }

    //checking for non alphabetical characters in the key
    for(int i = 0; i < key; i++)
    {
        char n = argv[1][i];
        if (isalpha(n) == 0)
        {
            printf("Your key contains non alpha characters, try again!\n");
            return 1;
        }

        //counting the number of letters in key and storing them in i.
    for(int Argv_letters = 0, key_len = strlen(argv[1]); Argv_letters < key_len; Argv_letters++)
    {
      // making k +1 greater than key letters and adding to k if its less.
      for(int k = Argv_letters + 1; k < key_len; k++)
            if (argv[1][Argv_letters] == argv[1][k] || isupper(argv[1][Argv_letters]) == isupper(argv[1][k]))
            {
                printf("we have duplicate");
                return 1;
            }
            
    }

    return true;

    }

Answer 1

您正在使用 isupper(argv[1][Argv_letters]) == isupper(argv[1][k]) 检查两个字母是否大小写相同。

您需要使用toupper(argv[1][Argv_letters]) == toupper(argv[1][k])来检查这两个字符是否代表相同的字母。

检查重复的字符没有给我想要的输出

Checking for repeated characters not giving me the desired output

c

cs50