백준 2909번: 캔디 구매

https://www.acmicpc.net/problem/2909

1. 문제

반올림 문제 

2. 알고리즘

키워드 - 구현

3. 코드

#include <iostream>
#include <sstream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <list>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <stack>
#include <math.h>
#include <memory.h>
 
using namespace std;
 
#define MAX_SIZE 100
#define INF 0x7fffffff
#define CENDL "\n"
#define ll long long
 
int main() {
 
    cin.tie(0);
    std::ios::sync_with_stdio(false);
 
    ll c, k, n =1;
    cin >> c >> k;
 
    for (int i=0; i<k; i++) {
        n = n * 10;
    }
 
    k = n / 10;
 
    cout << (c + (k * 5)) / (k * 10) * (k * 10) << CENDL;
    return 0;
}