Have Fun with Numbers及循环链表（约瑟夫问题）

1. 循环链表（约瑟夫问题）

https://github.com/BodhiXing/Data_Structure

2. Have Fun with Numbers

https://pta.patest.cn/pta/test/17/exam/4/question/263

#include <iostream>
#include <cstring>
using namespace std;


int main() {
    int a[10],b[10],buffer[21];
    char input[21];
    int i,j,len;
    int t,carry=0;
    
    memset(a,0,sizeof(a));  
    memset(b,0,sizeof(b));  
    
    cin>>input;
    len = strlen(input);
    //buffer中的数逆序 
    for(j=0,i=len-1; i>=0; i--,j++) {
        buffer[j] = input[i]-'0';
        a[buffer[j]]++;        //记录每个数出现的个数 
    }

    //数乘以2 
    carry=0;
    for(i=0; i<len; i++) {
        t =  buffer[i]*2;
        buffer[i] = (t+carry)%10;
        b[buffer[i]]++;
        carry =  (t+carry)/10;
    }

    
    for(j=0;j<10;j++){
        if(a[j] != b[j])
            break;
    }
    
    if(carry>0)
    {
        buffer[i]=carry;    
    }
    else
        i--;
    if(j<10) {
        cout<<"No"<<endl;
        for(; i>=0; i--)
            cout<<buffer[i];
    } else {
        cout<<"Yes"<<endl;
        for(; i>=0; i--)
            cout<<buffer[i];
    }

    return 0;
}