Submission #1089089

#	Time	Username	Problem	Language	Result	Execution time	Memory
1089089		kh0i	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	209 ms	15300 KiB

bridge

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

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif

using ll = long long;
using pii = pair<int, int>;

#define F first
#define S second
#define sz(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll get_rand(ll l, ll r) {
    assert(l <= r);
    return uniform_int_distribution<ll> (l, r)(rng);
}

int k, n;
vector<pair<ll, ll>> a;
ll res;

namespace Sub1{
    void solve(){
        vector<ll> x;
        for(auto [s, t] : a){
            x.push_back(s);
            x.push_back(t);
        }
        sort(all(x));

        ll pos = x[sz(x) / 2];
        for(ll k : x)
            res += abs(k - pos);

        cout << res + sz(a);
    }
}

struct SlidingMedian{
    multiset<ll> fi, se;
    ll sum_fi = 0, sum_se = 0;

    void add(ll x){
        se.insert(x);
        sum_se += x;
        while(sz(fi) < sz(se)){
            ll d = *se.begin();
            sum_se -= d;
            sum_fi += d;
            fi.insert(d);
            se.erase(se.begin());
        }
        while(sz(fi) > sz(se)){
            ll d = *fi.rbegin();
            sum_fi -= d;
            sum_se += d;
            se.insert(d);
            fi.erase(fi.find(d));
        }
    }

    ll get_sum(){
        ll med = *se.begin();
        return (1ll * sz(fi) * med - sum_fi) + (sum_se - 1ll * sz(se) * med);
    }

    void reset(){
        fi.clear();
        se.clear();
        sum_fi = sum_se = 0;
    }
};

namespace Sub2{
    void solve(){
        if(sz(a) == 0){
            cout << res;
            return;
        }

        sort(all(a), [](pair<ll, ll> &f, pair<ll, ll> &g) -> bool{
            return f.F + f.S < g.F + g.S;
        });

        vector<ll> pre(sz(a)), suf(sz(a));
        SlidingMedian st;
        for(int i = 0; i < sz(a); ++i){
            st.add(a[i].F);
            st.add(a[i].S);
            pre[i] = st.get_sum();
        }
        st.reset();
        for(int i = sz(a) - 1; i >= 0; --i){
            st.add(a[i].F);
            st.add(a[i].S);
            suf[i] = st.get_sum();
        }

        ll mn = suf[0];
        for(int i = 0; i < sz(a) - 1; ++i)
            mn = min(mn, pre[i] + suf[i + 1]);

        cout << res + mn + sz(a);
    }
}

void solve(){
    cin >> k >> n;
    for(int i = 1; i <= n; ++i){
        char p, q;
        int s, t;
        cin >> p >> s >> q >> t;
        if(p == q)
            res += abs(s - t);
        else{
            if(s > t)
                swap(s, t);
            a.push_back({s, t});
        }
    }

    if(k == 1)
        Sub1::solve();
    else
        Sub2::solve();
}

int32_t main() {
    cin.tie(nullptr)->sync_with_stdio(0);
    #define task "troll"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int test = 1;
//    cin >> test;
    for(int i = 1; i <= test; ++i){
//        cout << "Case #" << i << ": ";
        solve();
    }
    #ifdef LOCAL
        cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
    #endif
    return 0;
}

Compilation message (stderr)

bridge.cpp: In function 'int32_t main()':
bridge.cpp:138:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  138 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridge.cpp:139:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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