Submission #1124513

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124513		caterpillow	Lasers (NOI19_lasers)	C++17	0 / 100	0 ms	324 KiB

lasers

#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;
vector<pii> order;
int n,m,l,ans;
int main(){
    freopen("laser.txt","r",stdin);
    cin>>l>>n;
    for (int i=0;i<n;i++){
        vector<int> nw;int rtot=0,ltot=0;
        cin>>m;nw.resize(m);
        for (int j=0;j<m;j++){
            cin>>nw[j];rtot+=nw[j];
        }
        for (int j=0;j<m;j++){
            rtot-=nw[j];
            if (l-rtot-ltot<2*nw[j]){
                order.push_back({l-rtot-nw[j]+1,ltot+nw[j]});
            }
            ltot+=nw[j];
        }
    }
    sort(order.begin(),order.end());
    if (order.size()==0){
        cout<<0;
        return 0;
    }
    int prv=order[0].second,sub=order[0].second-order[0].first;
    for (pii i :order){
        if (i.second<=prv){
            continue;
        }
        if (i.first>prv){
            ans+=sub+1;
            sub = i.second-i.first;
            prv=i.second;
        }
        else{
            sub+=i.second-prv;
            prv=i.second;
        }
    }
    cout<<ans+sub+1;
}

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:7:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    7 |     freopen("laser.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 14
• Subtask 3: 0 / 20
• Subtask 4: 0 / 21
• Subtask 5: 0 / 22
• Subtask 6: 0 / 13