Submission #637953

#	Time	Username	Problem	Language	Result	Execution time	Memory
637953		ojoConmigo	Palembang Bridges (APIO15_bridge)	C++17	0 / 100	2075 ms	408 KiB

bridge

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

ll k,n;
vector<pair<ll,ll>> v;
vector<pair<int,pair<ll,ll>>> ordx,ordy;


ll f(ll puente){
    //cout << "puente: " << puente << endl;
    ll res = 0;
    for(auto par : v){
        ll x = par.first;
        ll y = par.second;
        if(x <= puente && puente <= y){
            res += (y-x+1);
        }else{
            res += (abs(puente - x) + abs(puente - y) + 1);
        }
        //cout << res << endl;
    }
    return res;
}

ll f2(ll puente,ll sol){
    ll lo = 0, hi = ordx.size()-1;
    ll res1 = ordx.size()-1,res2 = 0;
    while(lo <= hi){
        int mid = (lo+hi)/2;
        if(ordx[mid].second.first > puente){
            res1 = mid;
            hi = mid-1;
        }else{
            lo = mid+1;
        }
    }

    lo = 0; hi = ordy.size()-1;
    while(lo <= hi){
        int mid = (lo+hi)/2;
        if(ordy[mid].second.second < puente){
            res2 = mid;
            lo = mid+1;
        }else{
            hi = mid-1;
        }
    }

    vector<bool> usado(n,false);
    for(int i=0; i<res1+1; i++){
        ll x = ordx[i].second.first;
        ll y = ordx[i].second.second;
        ll ind = ordx[i].first;
        sol -= (y-x+1);
        sol += (abs(puente - x) + abs(puente - y) + 1);
        usado[ind] = true;
    }
    for(int i=res2; i<(int)ordy.size(); i++){
        ll ind = ordy[i].first;
        if(usado[ind])continue;
        ll x = ordy[i].second.first;
        ll y = ordy[i].second.second;
        sol -= (y-x+1);
        sol += (abs(puente - x) + abs(puente - y) + 1);
    }
    //cout << puente << " " << sol << endl;
    return sol;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> k >> n;
    ll sol = 0;
    ll mayor = 0;
    for(int i=0; i<n; i++){
        ll x,y;
        char a,b;
        cin >> a >> x >> b >> y;
        mayor = max(mayor,x);
        mayor = max(mayor,y);
        if(a == b){
            sol += abs(x-y);
        }else{
            if(x > y){
                swap(x,y);
            }
            v.push_back({x,y});
            ordx.push_back({i,{x,y}});
            ordy.push_back({i,{x,y}});
            //sol += (y-x+1);
        }
    }

    //ordx = ordy = v;
    /*
    sort(begin(ordx),end(ordx),[] (const auto & a, const auto & b){
        return a.second.first <= b.second.first;
    });
    sort(begin(ordy),end(ordy),[] (const auto & a, const auto & b){
        return a.second.second <= b.second.second;
    });
    */

    //Ternary search
    ll lb = 0, ub = mayor;
    while(lb+2 < ub){
        //cout << lb << " " << ub << endl;
        ll m1 = lb + (lb+ub)/3;
        ll m2 = ub - (lb+ub)/3;
        //cout << m1 << " " << f(m1) << " " << m2 << " " << f(m2) << endl;
        ll v1 = f(m1);
        ll v2 = f(m2);
        if(m1 > m2)break;
        if(v1 <= v2){
            ub = m2;
        }else{
            lb = m1;
        }
    }
    
    ll res = 1e18;
    for(ll i=lb; i<=ub; i++){
        res = min(res,f(i));
    }
    cout << res+sol << endl;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 14
• Subtask 3: 0 / 9
• Subtask 4: 0 / 32
• Subtask 5: 0 / 37