Submission #1193125

#	Time	Username	Problem	Language	Result	Execution time	Memory
1193125		loom	Lasers (NOI19_lasers)	C++20	100 / 100	88 ms	8620 KiB

lasers

#include<bits/stdc++.h>
using namespace std;
#define nl '\n'

inline void solve(){
   int l, r;
   cin>>l>>r;
   vector<pair<int,int>> v;

   for(int i=0; i<r; i++){
      int x;
      cin>>x;

      int a[x], sum = 0;
      for(int j=0; j<x; j++){
         cin>>a[j];
         sum += a[j];
      }

      int pre = 0, prev = l-sum+1;
      for(int j=0; j<x; j++){
         pre += a[j];
         if(pre >= prev){
            v.push_back({prev, 1});
            v.push_back({pre+1, -1});
         }
         prev = l-(sum-pre)+1;
      }
   }

   sort(v.begin(), v.end());
   int n = v.size();

   int ans = 0, cnt = 0;
   for(int i=0; i<n; i++){
      auto [x, c] = v[i];

      cnt += c;
      if(cnt > 0) ans += (i+1 < n ? v[i+1].first - x : l-x+1);
   }

   cout<<ans;
}

signed main(){
   ios_base::sync_with_stdio(0);
   cin.tie(NULL);cout.tie(NULL);

   int t = 1;
   //cin>>t;
   while(t--) solve();

   return 0;
}

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