Submission #1083190

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083190		damamila	Palembang Bridges (APIO15_bridge)	C++17	22 / 100	33 ms	6752 KiB

bridge

#include <bits/stdc++.h>

using namespace std;

#define int long long

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);  
	int k, n;
	cin >> k >> n;
	int m = n;
	vector<tuple<int, int, int>> num;
	vector<int> all;
	int ans = 0;
	for (int i = 0; i < n; i++) {
		int a, b;
		char c, d;
		cin >> c >> a >> d >> b;
		if (c == d) {
			m--;
			ans += abs(b-a);
		} else {
			ans++;
			all.push_back(a);
			all.push_back(b);
			num.push_back({a+b, a, b});
		}
	}
	sort(all.begin(), all.end());
	if (k == 1) {
		int x = all[all.size()/2];
		for (int i : all) {
			ans += abs(i-x);
		}
		cout << ans << endl;
	} else {
		sort(num.begin(), num.end());
		multiset<int> rbig;
		multiset<int> rsmall;
		multiset<int> lbig;
		multiset<int> lsmall;
		int rbigsum = 0, lbigsum = 0, rsmallsum = 0, lsmallsum = 0;
		for (int i = 0; i < all.size(); i++) {
			if (i <= all.size()/2) {
				rsmall.insert(all[i]);
				rsmallsum += all[i];
			} else {
				rbig.insert(all[i]);
				rbigsum += all[i];
			}
		}
		auto it = rsmall.end(); it--;
		int rmed = *it, lmed = 0;
		int res = 1e9; //biggest
		//~ cout << "YAYYYYY " << num.size() << endl;
		for (int i = 0; i < m-1; i++) {
			//~ cout << m << " " << i << endl;
			int tmp = 0; //ans for now
			auto [tot, a, b] = num[i];
			//remove from right
			if (a <= rmed) {
				rsmall.erase(rsmall.find(a));
				rsmallsum -= a;
			} else {
				rbig.erase(rbig.find(a));
				rbigsum -= a;
			}
			if (b <= rmed) {
				rsmall.erase(rsmall.find(b));
				rsmallsum -= b;
			} else {
				rbig.erase(rbig.find(b));
				rbigsum -= b;
			}
			//equalize right array lengths
			if (rbig.size() > rsmall.size()) {
				auto it = rbig.begin();
				rsmall.insert(*it);
				rbigsum -= *it;
				rsmallsum += *it;
				rbig.erase(rbig.begin());
			} 
			if (rsmall.size() > rbig.size()) {
				auto it = rsmall.end(); it--;
				rbig.insert(*it);
				rbigsum += *it;
				rsmallsum -= *it;
				rsmall.erase(it);
			}
			auto it = rsmall.end(); it--;
			int rmed = *it;
			//~ cout << "R DONE" << endl;
			//add to left
			if (a <= lmed) {
				lsmall.insert(a);
				lsmallsum += a;
			} else {
				lbig.insert(a);
				lbigsum += a;
			}
			if (b <= rmed) {
				lsmall.insert(b);
				lsmallsum += b;
			}
			else {
				lbig.insert(b);
				lbigsum += b;
			}
			//equalize left array lengths
			if (lbig.size() > lsmall.size()) {
				auto it = lbig.begin();
				lsmall.insert(*it);
				lsmallsum += *it;
				lbigsum -= *it;
				lbig.erase(it);
			}
			if (lsmall.size() > lbig.size()) {
				auto it = lsmall.end(); it--;
				lbig.insert(*it);
				lbigsum += *it;
				lsmallsum -= *it;
				lsmall.erase(it);
			}
			//calc left median
			it = lsmall.end(); it--;
			lmed = *it;
			//~ cout << "L DONE" << endl;
			//calc left sum
			tmp += abs(lbigsum-lsmallsum);
			//~ cout << lmed << ": " << tmp;
			//calc right sum
			tmp += abs(rbigsum-rsmallsum);
			//update ans
			res = min(res, tmp);
			//~ cout << " AAA " << rmed << ": " << tmp << endl;
		}
		cout << res+ans << endl;
	}
}

//change if to while if wa as may be multiple??
//changes infinities higher if wa

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:45:21: 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]
   45 |   for (int i = 0; i < all.size(); i++) {
      |                   ~~^~~~~~~~~~~~
bridge.cpp:46:10: 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]
   46 |    if (i <= all.size()/2) {
      |        ~~^~~~~~~~~~~~~~~

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