Problem 43 Sub-string divisibility （暴力...）

Sub-string divisibility

Problem 43

The number, 1406357289, is a 0 to 9 pandigital number because it is made up of each of the digits 0 to 9 in some order, but it also has a rather interesting sub-string divisibility property.

Let d₁ be the 1^st digit, d₂ be the 2^nd digit, and so on. In this way, we note the following:

• d₂d₃d₄=406 is divisible by 2
• d₃d₄d₅=063 is divisible by 3
• d₄d₅d₆=635 is divisible by 5
• d₅d₆d₇=357 is divisible by 7
• d₆d₇d₈=572 is divisible by 11
• d₇d₈d₉=728 is divisible by 13
• d₈d₉d₁₀=289 is divisible by 17

Find the sum of all 0 to 9 pandigital numbers with this property.

Answer:

16695334890Completed on Sun, 30 Oct 2016, 07:48

题解：无脑暴力....

代码：

#include<bits/stdc++.h>using namespace std;int main(){long long a[10]={0,1,2,3,4,5,6,7,8,9};int ans=0;unsigned long long sum=0;do{if((a[1]*100+a[2]*10+a[3])%2==0){if((a[2]*100+a[3]*10+a[4])%3==0){if((a[3]*100+a[4]*10+a[5])%5==0){if((a[4]*100+a[5]*10+a[6])%7==0){if((a[5]*100+a[6]*10+a[7])%11==0){if((a[6]*100+a[7]*10+a[8])%13==0){if((a[7]*100+a[8]*10+a[9])%17==0){ans++;sum+=(a[0]*1000000000+a[1]*100000000+a[2]*10000000+a[3]*1000000);sum+=(a[4]*100000+a[5]*10000+a[6]*1000+a[7]*100+a[8]*10+a[9]);cout<<a[0]<<a[1]<<a[2]<<a[3]<<a[4]<<a[5]<<a[6]<<a[7]<<a[8]<<a[9]<<endl;}}}}}}}}while(next_permutation(a,a+10));cout<<ans<<endl;cout<<sum<<endl;return 0;}