Codeforces Gym 100531D Digits 暴力

Problem D. Digits

题目连接：

http://codeforces.com/gym/100531/attachments

Description

Little Petya likes integers. Recently he has learned about different properties of sums of number’s digits.
For example, if the sum of number’s digits is divisible by 9, then the number itself is divisible by 9 as
well.
Now little Petya is interested in numbers with equal sum of digits. He asks his older brother Dima to find
n positive integers with equal sum of digits and minimal possible total sum. Dima has other important
things to do, so he asked you to write a program that solves this problem for him.

Input

Input file contains a single integer n (1 ≤ n ≤ 5000)

Output

Output the minimal possible sum of n positive integers, that all have same sum of digits.

Sample Input

2

Sample Output

11

Hint

题意

给你n，你需要找n个数，这n个数的数位和是相同的

求这n个数的最小和

题解：

千万不要想多了，直接暴力！

直接暴力。

代码

#include<bits/stdc++.h>
using namespace std;

int get(int x)
{
    int sum = 0;
    while(x)
    {
        sum += (x%10);
        x/=10;
    }
    return sum;
}
map<int,long long>ans;
map<int,long long>vis;
map<int,long long>sum;
int main()
{
    freopen("digits.in","r",stdin);
    freopen("digits.out","w",stdout);
    for(int i=1;i<=6000000;i++)
    {
        int k = get(i);
        vis[k]++;
        sum[k]+=i;
        if(ans[vis[k]]==0)
            ans[vis[k]]=sum[k];
        else
            ans[vis[k]]=min(ans[vis[k]],sum[k]);
    }
    int n;
    while(cin>>n)
        cout<<ans[n]<<endl;
}