Submission #994261

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Source Code Expand

#include<iostream>
#include<vector>
#include<cmath>
using namespace std;
typedef long long int lli;

int main(){
  lli n, a;
  std::cin >> n >> a;
  vector<lli> cost(n + 1, 1e9);
  cost[0] = 0;
  cost[1] = 1;
  for (int i = 2; i <= n; i++) {
    cost[i] = min(cost[i], (lli)i);
    for (int j = 2*i; j <= n; j+=i) {
      cost[j] = min(cost[j], cost[i] + j/i + a);
    }
  }
  lli ans = 1e9;
  for (int i = 1; i <= n; i++) {
    ans = min(ans, (lli)(ceil((double)(n)/i) + cost[i] + a));
  }
  std::cout << ans << std::endl;
  return 0;
}

Submission Info

Judge Result