Submission #60536

#	Time	Username	Problem	Language	Result	Execution time	Memory
60536		istlemin	Palembang Bridges (APIO15_bridge)	C++14	78 / 100	858 ms	35764 KiB

bridge

#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for(ll i = a; i < ll(b); ++i)
#define trav(a, v) for(auto& a : v)
#define all(x) x.begin(), x.end()
#define sz(x) (ll)(x).size()
#define D(x) cerr << #x << " = " << x << endl

typedef long long ll;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;

#include <ext/pb_ds/assoc_container.hpp> /** keep-include */
#include <ext/pb_ds/tree_policy.hpp> /** keep-include */

using namespace __gnu_pbds;

template <class T>
using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

int main() {
    cin.sync_with_stdio(false);
	ll k,n;
	ll totDist = 0;
	vector<pair<ll,pii>> intervals;
	cin>>k>>n;
	rep(i,0,n){
		char a,b;
		ll c,d;
		cin>>a>>c>>b>>d;
		if(a!=b){
			intervals.push_back(make_pair(c+d,pii(c,d)));
		}else{
			totDist += abs(c-d);
		}
	}
	ll bestDist = 0;
	if(intervals.size()>1){
		sort(all(intervals));
		vi rightTmp;
		vi leftTmp;
		rep(i,0,intervals.size()){
			if(i == 0){
				leftTmp.push_back(intervals[i].second.first);
				leftTmp.push_back(intervals[i].second.second);
			}else{
				rightTmp.push_back(intervals[i].second.first);
				rightTmp.push_back(intervals[i].second.second);
			}
		}
		multiset<ll> right(rightTmp.begin(),rightTmp.end());
		multiset<ll> left(leftTmp.begin(),leftTmp.end());
		auto rAt = right.begin();
		advance(rAt, right.size()/2);
		ll rIndex = right.size()/2;
		ll rSum = 0;
		for(auto it : right) rSum += abs(it - *rAt);
		auto lAt = left.begin();
		ll lIndex = 0;
		ll lSum = abs(intervals[0].second.second-intervals[0].second.first);
		bestDist = lSum + rSum;
		rep(i,1,intervals.size()-1){
			ll a = intervals[i].second.first;
			ll b = intervals[i].second.second;
			lSum += abs(*lAt-a) + abs(*lAt-b);
			rSum -= abs(*rAt-a) + abs(*rAt-b);
			vector<ll> p(2);
			p[0] = a; p[1] = b;
			rep(i,0,2){
				
				if(p[i]<*lAt) ++lIndex;
				left.insert(p[i]);
				
				if(p[i]==*rAt){
					auto eraseAt = rAt;
					if(rIndex>0){
						--rIndex;
						rAt = prev(rAt);
					}else{
						rAt = next(rAt);
					}
					right.erase(eraseAt);
				}else{
					if(p[i]<*rAt) --rIndex;
					right.erase(right.find(p[i]));
				}
			}
			if(lIndex>0){
				--lIndex;
				lAt = prev(lAt);
				lSum -= (lIndex*2 + 2 - left.size())*(*(next(lAt)) - *lAt);
			}
			if(rIndex>0){
				--rIndex;
				rAt = prev(rAt);
				rSum -= (rIndex*2 + 2 - right.size())*(*(next(rAt)) - *rAt);
			}
			//assert(distance(left.begin(),lAt)==lIndex);
			while(lIndex<left.size()/2){
				lSum += (lIndex*2 + 2 - left.size())*(*(next(lAt)) - *lAt);
				advance(lAt,1);
				++lIndex;
			}
			//assert(distance(right.begin(),rAt)==rIndex);
			while(rIndex<right.size()/2){
				rSum += (rIndex*2 + 2 - right.size())*(*(next(rAt)) - *rAt);
				advance(rAt,1);
				++rIndex;
			}
			bestDist = min(bestDist,lSum + rSum);
		}
	}else if(intervals.size()==1){
		bestDist = abs(intervals[0].second.second - intervals[0].second.first);
	}
	totDist += bestDist;
	totDist += intervals.size();
	cout<<totDist<<endl;
}



			/*left.insert(a);
			if(a<*lAt){
				++lIndex;
				//lAt = next(lAt);
			}
			left.insert(b);
			if(b<*lAt){
				++lIndex;
				//lAt = next(lAt);
			}
			rSum -= abs(*rAt-a) + abs(*rAt-b);
			if(a == *rAt){
				auto eraseAt = rAt;
				if(rIndex!=right.size()-1)
					rAt = next(rAt);
				else{
					rAt = prev(rAt);
					--rIndex;
				}
				right.erase(eraseAt);
				//rAt = prev(rAt);
			}else{
				if(a<*rAt){
					--rIndex;
					right.erase(right.lower_bound(a));
					//rAt = prev(rAt);
				}else{
					right.erase(right.lower_bound(a));
				}
			}
			if(b == *rAt){
				auto eraseAt = rAt;
				if(rIndex!=right.size()-1)
					rAt = next(rAt);
				else{
					rAt = prev(rAt);
					--rIndex;
				}
				right.erase(eraseAt);
				//rAt = prev(rAt);
			}else{
				if(b<*rAt){
					--rIndex;
					//rAt = prev(rAt);
				}
				right.erase(right.lower_bound(b));
			}
			if(lIndex>0){
				--lIndex;
				lAt = prev(lAt);
				--lIndex;
				lAt = prev(lAt);
			}
			if(rIndex>0){
				--rIndex;
				lAt = prev(lAt);
				--rIndex;
				lAt = prev(lAt);
			}*/

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:101:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(lIndex<left.size()/2){
          ~~~~~~^~~~~~~~~~~~~~
bridge.cpp:107:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(rIndex<right.size()/2){
          ~~~~~~^~~~~~~~~~~~~~~

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