Submission #536210

#	Time	Username	Problem	Language	Result	Execution time	Memory
536210		Tam_theguide	Palembang Bridges (APIO15_bridge)	C++14	100 / 100	347 ms	13652 KiB

bridge

#include <bits/stdc++.h>
using namespace std;
int n, k;

long long sameside=0;
vector<pair<int, int>>diff;
bool comp(pair<int, int>a, pair<int, int>b){
    return (a.first+a.second<b.first+b.second);
}
long long pre[100005];
multiset<int>low;
multiset<int>up;
long long lowsum=0;
long long upsum=0;
long long res=0;
void add(int x){
    if (low.size()==0){
        low.insert(x);
        lowsum+=x;
        return;
    }
    if (x<=*(--low.end())){
        low.insert(x);
        lowsum+=x;
    }else{
        up.insert(x);
        upsum+=x;
    }
}
long long ans=2e18;
void rebalance(){
    while (up.size()>low.size()){
        low.insert(*(up.begin()));
        lowsum+=*(up.begin());
        upsum-=*(up.begin());
        up.erase(up.begin());
    }
    while (low.size()>up.size()+1){
        up.insert(*(--low.end()));
        upsum+=*(--low.end());
        lowsum-=*(--low.end());
        low.erase(--low.end());
    }
}
void INSERT(int val){
    add(val);
    rebalance();
}
int main(){
    cin>>k>>n;
    for (int i=1;i <=n; i++){
        char a, b;
        int x, y;
        cin>>a>>x>>b>>y;
        if (a==b){
            sameside+=abs(x-y);
        }else{
            diff.push_back({x, y});
        }

    }
   // diff={{1, 1}, {2, 2}, {3, 4}, {5, 8}};
    int n_=diff.size();
    sameside+=n_;

    sort(diff.begin(), diff.end(), comp);

    for (int i=0; i<diff.size(); i++){
        INSERT(diff[i].first);
        INSERT(diff[i].second);
        pre[i]=*(--low.end())*((int)low.size())-lowsum+upsum-(*(--low.end())*((int)up.size()));
        //cout<<i<<" "<<pre[i]<<'\n';

    }
    ans=pre[n_-1];
    if (k==2){
        low.clear();
        up.clear();
        lowsum=upsum=0;
        for (int i=n_-1; i>=0; i--){
            INSERT(diff[i].first);
            INSERT(diff[i].second);
            ans=min(ans, *(--low.end())*((int)low.size())-lowsum+upsum-(*(--low.end())*((int)up.size())) + pre[i-1]);
        }
        cout<<ans+sameside;

    }else
    cout<<pre[n_-1]+sameside;



}

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:68:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |     for (int i=0; i<diff.size(); i++){
      |                   ~^~~~~~~~~~~~

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