题解 | 字符串排序

#include<bits/stdc++.h>
using namespace std;
bool isword(char ch)
{
    if((ch>='a'&&ch<='z') || (ch>='A'&&ch<='Z'))
    {
        return true;
    }
    else {
    return false;
    }
}

char bigtosmall(char a)
{
    if(a>='A'&&a<='Z')
    {
        return a + 'a'-'A';
    }
    else {
        return a;
    }
}

bool bigger(char a,char b)
{
    char ch1 = bigtosmall(a);
    char ch2 = bigtosmall(b);
    if(ch1>ch2)
    {
        return true;
    }
    else {
    return false;
    }
}

int main()
{
    string str;
    while(getline(cin,str))
    {
        int len1 = str.length();
        char ch[len1];
        int j = 0;
        for(int i = 0;i<len1;i++)
        {
            if(isword(str[i]))
            {
                ch[j++] = str[i];
            }
        }
        ch[j] = '\0';
        int len2 = strlen(ch);
        for(int i = 0;i<len2-1;i++)
        {
            for(int j = 0;j<len2-i-1;j++)
            {
                if(bigger(ch[j],ch[j+1]))
                {
                    char temp = ch[j];
                    ch[j] = ch[j+1];
                    ch[j+1] = temp;
                }
            }
        }

        int i = 0;
        j = 0;
        while(i<len1&&j<len2)
        {
            if(isword(str[i]))
            {
                str[i++] = ch[j++];
            }
            else
            {
                i++;
            }
        }
       cout<<str<<endl;
        
    }

    return 0;
}