7840 十全数

思路：非常经典的先循环，然后check(i)是否满足条件

 

#include<bits/stdc++.h>
#define f(i,s,e) for(int i = s; i <= e; i++)
#define ll long long
using namespace std;
const int N = 1e3+10,inf = 0x3f3f3f3f;
int check(int n)
{
    int sum = 0;
    while(n)
    {
        sum += n % 10;
        n /= 10;
    }
    return sum == 10;
}
int main()
{
    int k,sum = 0;
    cin >> k;
    for(int i = 1; ; i++)
    {
        if(check(i))sum++;
        if(sum == k){
            cout << i << endl;
            return 0;
        }
    }
    return 0;
}