Submission #380522

#	Time	Username	Problem	Language	Result	Execution time	Memory
380522		jass921026	Palembang Bridges (APIO15_bridge)	C++14	63 / 100	2077 ms	4200 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;
vector<int> pos, pos2;
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(s);
            pos.pb(t);
        }
    }
    ll ans=tmp;
    if(pos.empty()){
        cout<<tmp<<"\n";
        return 0;
    }
    sort(ALL(pos));
    sort(ALL(segs),cmp);
    int sz=segs.size();
    int bp=pos[sz];
    for(int i=0;i<sz;i++){
        if(segs[i].S<bp) ans+=2*(bp-segs[i].S);
        else if(segs[i].F>bp) ans+=2*(segs[i].F-bp);
    }
    if(k==1){
        cout<<ans<<"\n";
        return 0;
    }
    ll ans2=ans;
    for(int i=0;i<sz;i++){
        ll res=tmp;
        pos.clear();
        pos2.clear();
        for(int j=0;j<sz;j++){
            if(j<=i){
                pos.pb(segs[j].F);
                pos.pb(segs[j].S);
            } else{
                pos2.pb(segs[j].F);
                pos2.pb(segs[j].S);
            }
        }
        sort(ALL(pos));
        sort(ALL(pos2));
        int bp1=pos[pos.size()/2], bp2=pos2[pos2.size()/2];
        //cout<<bp1<<" "<<bp2<<"\n";
        for(int j=0;j<sz;j++){
            if(j<=i){
                if(segs[j].S<bp1) res+=2*(bp1-segs[j].S);
                else if(segs[j].F>bp1) res+=2*(segs[j].F-bp1);
            } else{
                if(segs[j].S<bp2) res+=2*(bp2-segs[j].S);
                else if(segs[j].F>bp2) res+=2*(segs[j].F-bp2);
            }
        }
        //cout<<i<<" "<<res<<"\n";
        ans2=min(ans2,res);
    }
    cout<<min(ans,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: 0 / 37