Problem 34 Digit factorials （暴力）

Digit factorials

Problem 34

145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145.

Find the sum of all numbers which are equal to the sum of the factorial of their digits.

Note: as 1! = 1 and 2! = 2 are not sums they are not included.

Answer:

40730Completed on Sat, 29 Oct 2016, 13:56

题解：暴力....

代码：

#include<bits/stdc++.h>using namespace std; int factorial(int n){    //return n==1 ? 1: n*factorial(n-1);    int sum=1;    for(int i=1;i<=n;i++) sum*=i; return sum;} int digit_factorial(int n){    int a=0,sum = 0;    while (n!=0)    {        sum += factorial(n % 10);        n /= 10;    }    return sum;} int main(){    vector<int> s;    for (int i=3;i<=999999;i++)    {        if(digit_factorial(i) == i)        {            s.push_back(i);        }    }     int sum=0;        for (vector<int>::iterator it=s.begin();it!=s.end();it++)    {        sum += *it;    }    cout<<sum<<endl;    return 0;}