题目描述

blablabla

样例

#include<bits/stdc++.h>
using namespace std;
int ar[9] = {1,2,3,4,5,6,7,8,9};

int sum(int i, int j){
    int ans = 0;
    for(int k = i;k <= j;k++)
        ans= ans*10 + ar[k];
    return ans;
}
int main(){
    int n, m,a ,an = 0;
    cin>>a;

    for(int i = 0;i < 362880;i++){  //9的全排类为362880个
        for(int j = 0;j < 7;j++)   //还是分三段
            {
                int re1 = sum(0,j);
                for(int k = j+1;k < 8;k++){
                    int re2 = sum(j+1,k);
                    int re3 = sum(k+1,8);
                    if(a*re3 == re1*re3+re2) an++;
                }
            }
            next_permutation(ar,ar+9); //  字典序+1后的全排列
    }
    cout<<an<<endl;
    return 0;
}