Submission #1001812

#	Time	Username	Problem	Language	Result	Execution time	Memory
1001812		vjudge1	Liteh and Newfiteh (INOI20_litehfiteh)	C++17	0 / 100	13 ms	1116 KiB

Main

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5+10;
map<pair<pair<int,int>,int>,int> mp;
int lg[N], n, a[N];
long long cnt=0;
int calc(int l, int r, int dec=0) {
  cnt++;
  if(mp.find({{l, r}, dec}) != mp.end()) {
    return mp[{{l,r},dec}];
  }
  if(lg[r-l+1] == 0)return -1;
  if(l == r) {
    if(a[l]-dec > 1)return -1;
    return a[l]-dec;
  }
  int mn = 1e9;
  for(int i = l;i<=r;i++) {
    mn=min(mn, a[i]-dec);
  }
  mn = (mn>0);
  int mid = (l+r)/2;
  long long L = calc(l, mid, dec+mn);
  long long R = calc(mid+1, r, dec+mn);
  if(L == -1 or R==-1)return -1;
  return mp[{{l,r},dec}]=L+R+mn;
}
int main () {
  {
    int cntlg=1;
    for(int i = 1;i<N;i*=2) {
      lg[i]=cntlg++;
    }
  }
  cin >> n;
  for(int i = 0;i<n;i++) {
    cin >> a[i];
  }
  long long dp[n+1];
  dp[0] = 0;
  for(int i= 1;i<=n;i++) {
    dp[i] = 1e18;
    for(int j = 1;j<=i;j*=2) {
      long long val = calc(i-j, i-1);
      if(val == -1)continue;
      dp[i] = min(dp[i], dp[i-j] + val);
    }
  }
  assert(cnt<=100*n);
  if(dp[n] == 1e18)cout << "-1\n";
  else cout << dp[n] << "\n";
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 70