Submission #1063517

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063517		DeathIsAwe	Palembang Bridges (APIO15_bridge)	C++17	31 / 100	113 ms	14772 KiB

bridge

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int long long


bool compare(pair<int,int> a, pair<int,int> b) {
    if (a.first == b.first) {
        return a.second > b.second;
    }
    return a.first < b.first;
}


int32_t main() {
    char p, q;
    int s, t, k, n; cin >> k >> n;
    ll ans = 0;
    unordered_map<int,int> bruh;
    unordered_map<int,int> sus;
    vector<int> bridgeplaces;
    vector<pair<int, int>> housework;


    if (k == 2) {
    ll baseans = 0;
    for (int i=0;i<n;i++) {
        cin >> p >> s >> q >> t;
        if (p == q) {
            baseans += abs(s - t);
            continue;
        }
        if (t > s) {
            swap(t, s);
        }
        housework.push_back(make_pair(s + t, s - t));
    }
    n = housework.size();
    if (n == 0) {
        cout << baseans;
        return 0;
    }
    if (n == 1) {
        cout << baseans + housework[0].second + 1;
      	return 0;
    }


    unordered_set<int> posset;
    pair<int,int> dum;
    vector<int> posplaces;
    for (int i=0;i<n;i++) {
        if (posset.find((housework[i].first - housework[i].second) / 2) == posset.end()) {
            posset.insert((housework[i].first - housework[i].second) / 2);
            posplaces.push_back((housework[i].first - housework[i].second) / 2);
        }
        if (posset.find((housework[i].first + housework[i].second) / 2) == posset.end()) {
            posset.insert((housework[i].first + housework[i].second) / 2);
            posplaces.push_back((housework[i].first + housework[i].second) / 2);
        }
    }


    sort(posplaces.begin(), posplaces.end());
    sort(housework.begin(), housework.end(), compare);
    vector<int> ansright(n-1), ansleft(n-1);
    priority_queue<int, vector<int>, greater<int>> lefttown, righttown;
    ll ahead = 0, behind = 0, curpos = 0, sigma, tate; ans = 0;
    for (int i=0;i<n-1;i++) {
        ans += housework[i].second + 1;
        sigma = (housework[i].first - housework[i].second) / 2;
        tate = (housework[i].first + housework[i].second) / 2;
        if (sigma > posplaces[curpos]) {
            ahead++;
            ans += 2 * (sigma - posplaces[curpos]);
            lefttown.push(sigma);
        }
        if (tate == posplaces[curpos]) {
            behind++;
        } else {
            righttown.push(tate);
        }
        while (ahead > behind) {
            curpos++;
            ans -= 2*(ahead - behind)*(posplaces[curpos] - posplaces[curpos - 1]);
            while (!lefttown.empty() && lefttown.top() == posplaces[curpos]) {
                lefttown.pop();
                ahead--;
            }
            while (!righttown.empty() && righttown.top() == posplaces[curpos]) {
                righttown.pop();
                behind++;
            }
        }
        //cout << posplaces[curpos] << '\n';
        ansleft[i] = ans;
    }


    priority_queue<int> lefttown2, righttown2;
    ahead = 0; behind = 0; curpos = posplaces.size() - 1; ans = 0;
    for (int i=n-1;i>0;i--) {
        ans += housework[i].second + 1;
        sigma = (housework[i].first - housework[i].second) / 2;
        tate = (housework[i].first + housework[i].second) / 2;
        if (tate < posplaces[curpos]) {
            ahead++;
            ans += 2 * (posplaces[curpos] - tate);
            righttown2.push(tate);
        }
        if (sigma == posplaces[curpos]) {
            behind++;
        } else {
            lefttown.push(sigma);
        }
        lefttown2.push(sigma);
        while (ahead > behind) {
            curpos--;
            ans -= 2*(ahead - behind)*(posplaces[curpos + 1] - posplaces[curpos]);
            while (!righttown2.empty() && righttown2.top() == posplaces[curpos]) {
                righttown2.pop();
                ahead--;
            }
            while (!lefttown2.empty() && lefttown2.top() == posplaces[curpos]) {
                lefttown2.pop();
                behind++;
            }
        }
        ansright[i - 1] = ans;
    }


    //for (int i=0;i<n-1;i++) {
    //    cout << ansright[i] << ' ';
    //} cout << '\n';
    //for (int i=0;i<n-1;i++) {
    //    cout << ansleft[i] << ' ';
    //} cout << '\n';


    ll realans = INT64_MAX;
    for (int i=0;i<n-1;i++) {
        realans = min(realans, ansleft[i] + ansright[i]);
    }
    cout << realans + baseans;


    return 0;
    }


    ll ahead = 0;
    for (int i=0;i<n;i++) {
        cin >> p >> s >> q >> t;
        if (t > s) {
            swap(t, s);
        }
        if (p == q) {
            ans += abs(s - t);
            continue;
        }
        ahead++;
        housework.push_back(make_pair(t, s));
        if (bruh.find(s) == bruh.end()) {
            bruh[s] = 1;
            if (sus.find(s) == sus.end()) {
                bridgeplaces.push_back(s);
            }
        } else {
            bruh[s]++;
        }
        if (sus.find(t) == sus.end()) {
            sus[t] = 1;
            if (bruh.find(t) == bruh.end()) {
                bridgeplaces.push_back(t);
            }
        } else {
            sus[t]++;
        }
    }


    sort(bridgeplaces.begin(), bridgeplaces.end());
    for (pair<int,int> i: housework) {
        ans += i.first + i.second + 1;
    }
    ll curans = ans;
    ll prev = 0;
    ll visitednum = 0;
    for (int i=0;i<bridgeplaces.size();i++) {
        curans += 2 * (bridgeplaces[i] - prev) * (visitednum - ahead);
        //cout << visitednum << ' ' << ahead << ' ' << bridgeplaces[i] << ' ' << curans << '\n';
        if (bruh.find(bridgeplaces[i]) != bruh.end()) {
            visitednum += bruh[bridgeplaces[i]];
        }
        if (sus.find(bridgeplaces[i]) != sus.end()) {
            ahead -= sus[bridgeplaces[i]];
        }
        ans = min(ans, curans);
        prev = bridgeplaces[i];
    }
    cout << ans;
}

Compilation message (stderr)

bridge.cpp: In function 'int32_t main()':
bridge.cpp:190:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  190 |     for (int i=0;i<bridgeplaces.size();i++) {
      |                  ~^~~~~~~~~~~~~~~~~~~~

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