Submission #1160649

#	Time	Username	Problem	Language	Result	Execution time	Memory
1160649		guagua0407	Arranging Tickets (JOI17_arranging_tickets)	C++20	100 / 100	899 ms	16932 KiB

arranging_tickets

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

int main() {_
    int n,m;
    cin>>n>>m;
    vector<ll> l(m),r(m),c(m);
    vector<vector<int>> id(n+1);
    vector<ll> pre(n+2);
    for(int i=0;i<m;i++){
        cin>>l[i]>>r[i]>>c[i];
        if(l[i]>r[i]) swap(l[i],r[i]);
        id[l[i]].push_back(i);
        pre[l[i]]+=c[i];
        pre[r[i]]-=c[i];
    }
    for(int i=1;i<=n;i++){
        pre[i]+=pre[i-1];
    }
    int pos=max_element(all(pre))-pre.begin();
    //cout<<pos<<'\n';
    assert(1<=pos and pos<=n);
    auto check=[&](ll ans,int d){
        priority_queue<pair<int,pair<int,ll>>> pq;
        ll pt=pre[pos]-ans+d;
        ll px=0;
        vector<ll> pre2(n+2);
        for(int i=1;i<=pos;i++){
            for(auto v:id[i]){
                if(r[v]>pos) pq.push({r[v],{v,c[v]}});
            }
            ll tp=(pre[i]+pt-ans+1)/2;
            while(px<tp){
                if(pq.empty()) return false;
                auto v=pq.top();
                pq.pop();
                ll dif=min(v.s.s,tp-px);
                px+=dif;
                pre2[1]+=dif;
                pre2[l[v.s.f]]-=2*dif;
                pre2[r[v.s.f]]+=2*dif;
                v.s.s-=dif;
                if(v.s.s>0) pq.push(v);
            }
        }
        ll sum=0;
        for(int i=1;i<=n;i++){
            sum+=pre2[i];
            if(pre[i]+sum>ans) return false;
        }
        return true;
    };
    ll L=0,R=*max_element(all(pre));
    while(L<R){
        ll mid=(L+R)/2;
        if(check(mid,0) or check(mid,1)){
            R=mid;
        }
        else{
            L=mid+1;
        }
    }
    cout<<L<<'\n';
    return 0;
}
//maybe its multiset not set
//yeeorz
//diaoborz

Compilation message (stderr)

arranging_tickets.cpp: In function 'void setIO(std::string)':
arranging_tickets.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arranging_tickets.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 35 / 35
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 15 / 15