Submission #643015

#	Time	Username	Problem	Language	Result	Execution time	Memory
643015		devariaota	Lasers (NOI19_lasers)	C++17	100 / 100	301 ms	13940 KiB

lasers

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
const ll MOD=1e9+7;
using namespace std;
ll N,M,s[500005];
vector <pair<ll,ll> > vec;
int main(){
  cin>>N>>M;
  for(int i=1;i<=M;i++){
    cin>>s[i];
    ll a[s[i]+2];
    ll pref[s[i]+2];
    ll suff[s[i]+2];
    for(int j=1;j<=s[i];j++){
      ll y;
      cin>>y;
      a[j]=y;
    }
    pref[0]=0;
    suff[s[i]+1]=0;
    for(int j=1;j<=s[i];j++){
      pref[j]=pref[j-1]+a[j];
    }
    for(int j=s[i];j>=1;j--){
      suff[j]=suff[j+1]+a[j];
    }
    for(int j=1;j<=s[i];j++){
      ll l=N-suff[j]+1;
      ll r=pref[j];
      if(l<=r){
        vec.push_back({l,r});
      }
    }
  }
  sort(vec.begin(),vec.end());
  if(vec.empty()){
    cout<<0<<endl;
    return 0;
  }
  ll l=vec[0].fi;
  ll r=vec[0].se;
  ll ans=r-l+1;
  for(int i=1;i<vec.size();i++){
    if(vec[i].fi>r){
      ans+=vec[i].se-vec[i].fi+1;
      l=vec[i].fi;
      r=vec[i].se;
    }
    else if(vec[i].se>r){
      ans+=vec[i].se-r;
      l=vec[i].fi;
      r=vec[i].se;
    }
  }
  cout<<ans<<endl;
}
/*
20 6
1 8
2 2 8
3 2 2 8
4 2 2 2 8
5 2 2 2 2 8
6 2 2 2 2 2 8
*/

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:46:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |   for(int i=1;i<vec.size();i++){
      |               ~^~~~~~~~~~~

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