Submission #645468

#	Time	Username	Problem	Language	Result	Execution time	Memory
645468		kith14	Lasers (NOI19_lasers)	C++14	100 / 100	395 ms	31624 KiB

lasers

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define db double
#define pairll pair<ll,ll>
#define lpairll pair<ll,pairll>

#define repp(i,a,b) for (ll i = a; i <= b; i++)
#define repz(i,a,b) for (ll i = a; i < b; i++)
#define repm(i,a,b) for (ll i = a; i >= b; i--)
#define fr first
#define sc second
#define x first
#define y second
#define mp make_pair
#define pb push_back

const ll N = 5e5+5, MOD = 1e9+7;
ll tc = 1, n, m, ar[N], br[N];
ll k, len;
string s, s1, s2, ye = "YA", no = "TIDAK";
map<ll,ll> mapz;
vector<ll> v;
vector<pairll> cmp;

void input(){
  cin >> len >> n;
  repp(j,1,n){
    //cout << "i = " << j << endl;
    cin >> k;
    v.clear();
    cmp.clear();
    ll rig = 0, lef = 0;
    while(k--){
      cin >> m;
      v.pb(m);
      rig += m;
    }
    for (auto i : v){
      cmp.pb(mp(lef+1,len-rig));
      rig -= i;
      lef += i;
    }
    cmp.pb(mp(lef+1,len));
    ll l = cmp[0].fr, r = cmp[0].sc;   
    for (auto i : cmp){
      //cout << i.fr << " " << i.sc << endl;
      if (i.fr > r){
        mapz[l]++;
        mapz[r+1]--;
        //cout << l << " " << r << endl;
        l = i.fr;
        r = i.sc;
      }
      else r = max(r,i.sc);
    }
    mapz[l]++;
    mapz[r+1]--;
    //cout << l << " " << r << endl;
  }
}

void solve(){
  ll ans = 0, cur = 0, pre = -1;
  for (auto it = mapz.begin(); it != mapz.end(); ++it){
    ll key = it -> first, val = it->second;
    cur += val;
    //cout << "mapz = " << key << " " << cur << endl;
    if (cur < n && pre != -1){
      ans += key-pre;
      //cout << key << " " << pre << endl;
      pre = -1;
    }
    else if (pre == -1 && cur == n) pre = key;
  }
  cout << len-ans << endl;
}

int main(){
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  //cin >> tc;
  while(tc--){
    input();
    solve();
  }
}

• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 20 / 20
• Subtask 4: 21 / 21
• Subtask 5: 22 / 22
• Subtask 6: 13 / 13