Submission #805374

#	Time	Username	Problem	Language	Result	Execution time	Memory
805374		nonono	Palembang Bridges (APIO15_bridge)	C++14	100 / 100	225 ms	16112 KiB

bridge

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

const int INF = 1e18;
const int mxN = 1e5 + 10;

int n, k;
char p[mxN], q[mxN];
int s[mxN], t[mxN];

namespace full {
    
    multiset<int> L, R;
    int sumL = 0, sumR = 0;
    int f1[mxN], f2[mxN];
    
    int calc() {
        int tmp = INF;
        
        if(L.size() > 0) {
            int l = *(-- L.end());
            tmp = min(tmp, l * (long long)L.size() - sumL + sumR - l * (long long)R.size());
        }
        
        if(R.size() > 0) {
            int r = *R.begin();
            tmp = min(tmp, r * (long long)L.size() - sumL + sumR - r * (long long)R.size());
        }
        
        return tmp;
    }
    
    void add(int x) {
        if(L.size() > 0 && *(-- L.end()) > x) {
            sumL += x;
            L.insert(x);
        } else {
            sumR += x;
            R.insert(x);
        }
    
        while(L.size() > R.size() + 1) {
            sumR += *(-- L.end());
            R.insert(*(-- L.end()));
            
            sumL -= *(-- L.end());
            L.erase(-- L.end());
        }
        
        while(R.size() > L.size()) {
            sumL += *R.begin();
            L.insert(*R.begin());
            
            sumR -= *R.begin();
            R.erase(R.begin());
        }
    }
    
    void solve() {
        
        int sum = 0;
        vector<int> ar;
        
        for(int i = 1; i <= n; i ++) {
            if(p[i] == q[i]) sum += abs(s[i] - t[i]);
            else {
                ar.push_back(i);
            }
        }
        
        sort(ar.begin(), ar.end(), [&](const int &x, const int &y) {
            return s[x] + t[x] < s[y] + t[y]; 
        });
        
        for(int i = 0; i < ar.size(); i ++) {
            int id = ar[i];
            add(s[id]);
            add(t[id]);
            f1[i] = calc();
        }
    
        L.clear(); R.clear();
        sumL = 0; sumR = 0;
        
        for(int i = ar.size() - 1; i >= 0; i --) {
            int id = ar[i];
            add(s[id]);
            add(t[id]);
            f2[i] = calc();
        }
        
        int result = INF;
        
        if(k >= 1) result = min({result, f1[ar.size() - 1], f2[0]});
        
        if(k >= 2) {
            for(int i = 0; i + 1 < ar.size(); i ++) {
                result = min(result, f1[i] + f2[i + 1]);
            }
        }
        
        cout << sum + result + ar.size() << "\n";
    }
}

signed main() {
    
    cin.tie(0)->sync_with_stdio(0);
    
    cin >> k >> n;
    
    for(int i = 1; i <= n; i ++) cin >> p[i] >> s[i] >> q[i] >> t[i];
    
    full::solve();
    return 0;
}

Compilation message (stderr)

bridge.cpp: In function 'void full::solve()':
bridge.cpp:76:26: 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]
   76 |         for(int i = 0; i < ar.size(); i ++) {
      |                        ~~^~~~~~~~~~~
bridge.cpp:98:34: 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]
   98 |             for(int i = 0; i + 1 < ar.size(); i ++) {
      |                            ~~~~~~^~~~~~~~~~~

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