Submission #1268325

#	Time	Username	Problem	Language	Result	Execution time	Memory
1268325		nadeshiko	Lasers (NOI19_lasers)	C++20	0 / 100	110 ms	22944 KiB

lasers

#include <bits/stdc++.h>

using namespace std;

int main()
{
    long long Len,r;
    cin>>Len>>r;
    vector<pair<long long,long long>>ev;
    for(int j=0; j<r; j++)
    {
        long long n;
        cin>>n;
        vector<long long>a(n);
        for(int i=0; i<n; i++)cin>>a[i];
        vector<long long>pref(n+1,0);
        vector<long long>suff(n+2,0);
        for(int i=1; i<=n; i++)
        {
            pref[i]=pref[i-1]+a[i-1];
        }
        for(int i=n; i>=1; i--)
        {
            suff[i]=suff[i+1]+a[i-1];
        }
        for(int i=1; i<=n; i++)
        {
            long long x=pref[i];
            long long y=suff[i];
            if(x+y>=Len)
            {
                long long l=Len-y;
                long long rpos=x;
                if(l<1) l=1;
                if(l<=rpos)
                {
                    ev.push_back({l+1,rpos});
                }
            }
        }
    }
    long long ans=0;
    vector<long long>ps;
    for(auto [l,rpos]:ev)
    {
        ps.push_back(l);
        ps.push_back(rpos+1);

    }
    ps.push_back(1);
    ps.push_back(Len+1);
    sort(ps.begin(),ps.end());
    ps.erase(unique(ps.begin(),ps.end()),ps.end());
    unordered_map<long long,long long>id;
    for(int i=0;i<ps.size();i++){
        id[ps[i]]=i;
    }
    vector<long long>diff(ps.size()+1,0);
    for(auto &p:ev){
        diff[id[p.first]]++;
        diff[id[p.second+1]]--;
    }
    long long cur=0;
    for(int i=0;i+1<ps.size();i++){
        cur+=diff[i];
        if(cur>0)ans+=ps[i+1]-ps[i];
    }
    cout<<ans;
}

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