Submission #380803

#	Time	Username	Problem	Language	Result	Execution time	Memory
380803		jass921026	Palembang Bridges (APIO15_bridge)	C++14	100 / 100	399 ms	14420 KiB

bridge

#include<bits/stdc++.h>
using namespace std;
#define jizz ios_base::sync_with_stdio(false);cin.tie(NULL);
typedef long long ll;
typedef pair<int,int> pii;
#define F first
#define S second
#define ALL(x) (x).begin(),(x).end()
#define pb push_back
#define mkp make_pair
bool cmp(pii a, pii b){
    return a.F+a.S<b.F+b.S;
}
int abs(int x){
    return x>0?x:-x;
}
vector<pii> segs, pos;
map<int,int> ls, lb, rs, rb;
void add(map<int,int> &mp, int pos){
    mp[pos]++;
}
void del(map<int,int> &mp, int pos){
    mp[pos]--;
    if(mp[pos]==0) mp.erase(pos);
}
int main(){ jizz
    int k, n;
    cin>>k>>n;
    ll tmp=0;
    for(int i=0;i<n;i++){
        char p, q;
        int s, t;
        cin>>p>>s>>q>>t;
        if(s>t) swap(s,t);
        tmp+=(t-s);
        if(p!=q) {
            tmp++;
            segs.pb(mkp(s,t));
            pos.pb(mkp(s,0));
            pos.pb(mkp(t,1));
        }
    }
    ll ans=tmp;
    if(segs.empty()){
        cout<<tmp<<"\n";
        return 0;
    }
    sort(ALL(segs),cmp);
    sort(ALL(pos));
    int sz=segs.size();
    ll lsum=0, rsum=0;
    for(int i=0;i<sz;i++){
        add(rs,pos[i].F);
        if(pos[i].S==1) rsum-=2*(pos[i].F);
    }
    for(int i=sz;i<sz*2;i++){
        add(rb,pos[i].F);
        if(pos[i].S==0) rsum+=2*(pos[i].F);
    }
    if(k==1){
        cout<<ans+lsum+rsum<<"\n";
        return 0;
    }
    //cout<<lsum<<" "<<rsum<<"\n";
    ll ans2=ans+lsum+rsum;
    for(int i=0;i<sz;i++){
        /*cout<<"rs=\n";
        for(auto j:rs){
            cout<<j.F<<" "<<j.S<<"\n";
        }
        cout<<"rb=\n";
        for(auto j:rb){
            cout<<j.F<<" "<<j.S<<"\n";
        }
        cout<<"ls=\n";
        for(auto j:ls){
            cout<<j.F<<" "<<j.S<<"\n";
        }
        cout<<"lb=\n";
        for(auto j:lb){
            cout<<j.F<<" "<<j.S<<"\n";
        }*/
        del(rs,segs[i].F);
        if(segs[i].S<rb.begin()->F){
            del(rs,segs[i].S);
            rsum+=2*segs[i].S;
            auto p=rb.begin();
            rsum-=2*(p->F);
            del(rb,p->F);
            add(rs,p->F);
        } else{
            del(rb,segs[i].S);
        }
        add(lb,segs[i].S);
        if(segs[i].F<lb.begin()->F){
            add(ls,segs[i].F);
        } else{
            add(lb,segs[i].F);
            lsum+=2*segs[i].F;
            auto p=lb.begin();
            lsum-=2*(p->F);
            del(lb,p->F);
            add(ls,p->F);
        }
        //cout<<lsum<<" "<<rsum<<"\n";
        ans2=min(ans2,ans+lsum+rsum);
    }
    cout<<ans2<<"\n";
    return 0;
}
/*
1 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
2 3
A 3 B 3
A 4 B 4
A 5 B 5
*/

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37