更小的数(不用真调换，只需要比较首位指针)

解题思路:

注意事项:

string类型用    .length()

char字符数组char s[20]用    strlen(s)

参考代码:

#include<iostream>
#include<string.h>
using namespace std;
int main()
{
    string s;
    cin>>s;
    int l=0,r=0,max=s.length(),count=0;
    for(l=0;l<=max-2;l++)
    {
        for(r=l+1;r<=max-1;r++)
        {
            if(s[l]>s[r]) count++;
            else if(s[l]<s[r]) ;
            else {
                int l1=l+1,r1=r-1;
                while(l1<=r1)
                {
                    if(s[l1]>s[r1])
                    {
                        count++;
                        break;
                    }
                    else if(s[l1]<s[r1]) break;
                    else
                    {
                        l1++;
                        r1--;
                    }
                }
            }
        }
    }
    cout<<count;
    return 0;
}