Submission #993678

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll N,A;
ll dp[1000005];
ll solve(ll n){
  if( dp[n] != -1 ) return dp[n];
  ll res = n;
  if( n == 0 ) return dp[n] = 0;
  for(int i=2;i<=n/2;i++){
    ll ret = (n+i-1)/i + solve( i ) + A;
    if( n > ret || res*2 > ret )
      res = min( res, ret );
    else {
      break;
    }
  }
  //  cout << n << ": " << res << endl;
  return dp[n] = res;
}
int main(){
  memset( dp,-1,sizeof( dp ) );
  cin >> N >> A;
  if( N > 1000000LL ) return 0;
  cout << solve( N ) << endl;
}

Submission Info

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