每日一题04_带分数

#include<iostream>

#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;
int n;//被拆分的值
int st[15];
bool used[15];
int a, b, c, cnt;
int cal(int a, int b)
{
int res = 0;
for (int i = a; i <= b; i++)
{
res = res * 10 + st[i];
}
return res;
}
void dfs(int u)
{
if (u >9)
{
for (int i = 1; i <= 7; i++)
{
for (int k = i + 1; k <= 8; k++)
{
a = cal(0, i);
b = cal(i + 1, k);
c = cal(k + 1, 9);
if (n*c - a * c == b)

{
cnt++;
}
}
}
return;
}
for (int i = 1; i <= 9; i++)
{
if(!used[i])
{
used[i] = true;
st[u] = i;
dfs(u + 1);
used[i] = false;
st[u] = 0;
}

}
return;
}
int main()
{
cin >> n;
dfs(1);
cout << cnt;
// system("pause");
return 0;
}