BOJ 17173 - 배수들의 합 [C++]

문제

링크

풀이

#include <iostream>
#include <vector>
using namespace std;
 
void solve(void) {
  int n, m; cin >> n >> m;
  vector<int> k(m);
  for (int i=0; i<m; i++) cin >> k[i];
 
  vector<bool> ok(n+1, false);
  for (int i=0; i<m; i++) {
    for (int j=k[i]; j<=n; j+=k[i]) ok[j] = true;
  }
 
  int ans = 0;
  for (int i=1; i<=n; i++) {
    if (ok[i]) ans += i;
  }
  cout << ans;
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}