Submission #1007864

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007864		devariaota	Lasers (NOI19_lasers)	C++17	100 / 100	202 ms	46212 KiB

lasers

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define pb push_back
#define pii pair<ll,ll>
#define fi first
#define sec second
#define endl '\n'
#define ordered_set tree<ll, null_type,less<ll>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset tree<ll, null_type,  less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update> 

const ll MOD = 998244353;
const ll N = 5e5 + 5;
const ll INF = 1e18;

vector<ll>vec[N];

int32_t main(){
  cin.tie(0)->sync_with_stdio(0);
  int tc = 1;
  // cin >> tc;
  while(tc--){
    ll n,q; cin >> n >> q;
    for(int i=1;i<=q;i++){
      ll a; cin >> a;
      for(int j=1;j<=a;j++){
        ll x; cin >> x;
        vec[i].pb(x);
      }
    }
    set<pii>interval;
    for(int i=1;i<=q;i++){
      ll l = 1;
      vector<ll>suff(vec[i].size() + 5);
      for(int j=vec[i].size();j>=0;j--){
        if(j == vec[i].size()-1) suff[j] = vec[i][j];
        else suff[j] = suff[j+1] + vec[i][j];
      }
      for(int j=0;j<vec[i].size();j++){
        ll val = max(0LL, 2*vec[i][j] - (n-(j == vec[i].size()-1 ? 0 : suff[j+1])-l+1));
        if(val > 0) interval.insert({l-val+vec[i][j], l+vec[i][j]-1});
        l += vec[i][j];
      }
    }
    if(interval.size() == 0){
      cout << 0 << endl;
      continue;
    }
    ll last = -1, prev = -1, mx = 0, ans = 0;
    for(auto i : interval){
      if(prev == -1) prev = i.fi;
      if(i.fi != prev){
        ans += max(0LL, last - max(prev - 1,mx));
        mx = max(mx, last);
        prev = i.fi;
        last = 0;
      }
      last = i.sec;
    }
    ans += max(0LL, last - max(prev - 1,mx));
    cout << ans << endl;
  }
}
/*
1 2 3 4 5 6 7 8 9 10 11
*/

Compilation message (stderr)

lasers.cpp: In function 'int32_t main()':
lasers.cpp:39:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         if(j == vec[i].size()-1) suff[j] = vec[i][j];
      |            ~~^~~~~~~~~~~~~~~~~~
lasers.cpp:42:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |       for(int j=0;j<vec[i].size();j++){
      |                   ~^~~~~~~~~~~~~~
lasers.cpp:43:47: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         ll val = max(0LL, 2*vec[i][j] - (n-(j == vec[i].size()-1 ? 0 : suff[j+1])-l+1));
      |                                             ~~^~~~~~~~~~~~~~~~~~

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