P8599 [蓝桥杯 2013 省 B] 带分数

P8599 [蓝桥杯 2013 省 B] 带分数

暴力，全排列

#include<bits/stdc++.h>
using namespace std;
int a[11]={0,1,2,3,4,5,6,7,8,9};
int m,ans;
int tosum(int l,int r)
{
    int s=0;
    for(int i=l;i<=r;i++)
    {
        s=s*10+a[i];
    }
    return s;
}
int main()
{
    scanf("%d",&m);
    int first,second,third;
    do
    {
        for(int i=1;i<9;i++)
        {
            for(int j=i+1;j<9;j++)
            {    
                first=tosum(0,i);
                second=tosum(i+1,j);
                third=tosum(j+1,9);
                //printf("%d %d %d\n",first,second,third);
                if((m-first)*third==second)
                ans++;
            }
        }
    }while(next_permutation(a+1,a+10));
    printf("%d",ans);
    return 0;
}