题解 | #带分数#

#include<algorithm>
using namespace std;
int num[9] = {1,2,3,4,5,6,7,8,9};

int lenof(int x){
    int len = 0;
    while(x){
        x/=10;
        len++;
    }
    return len;
}

int numof(int a,int b){
    int num_x=0;
    for(int i=a;i<=b;i++){
        num_x = num_x*10 + num[i];
    }
    return num_x;
}

int main()
{
    int n;
    cin >> n;
    int size = lenof(n);
    int sum=0,a,b,c;
    do{for(int i=0;i<=size;i++){
            for(int j=i+1;j<8;j++){
                a = numof(0,i);
                b = numof(i+1,j);
                c = numof(j+1,8);
                if((long long)(n*c) == (long long)(a*c+b)) sum++;
            }
        }
    }while(next_permutation(num,num+9));
    cout << n << " " << sum << endl;
    system("pause");
    return 0;
}