Submission #544930

#	Time	Username	Problem	Language	Result	Execution time	Memory
544930		benson1029	Reconstruction Project (JOI22_reconstruction)	C++14	7 / 100	5085 ms	816024 KiB

reconstruction

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

int n,m,q,w;
pair< int, pair<int,int> > ed[100005];
vector<int> used[100005], used2[100005], v[100005];
int dsu[505];

int find(int x) {
	if(dsu[x]==x) return x;
	else return dsu[x] = find(dsu[x]);
}

void merge(int x, int y) {
	dsu[find(x)] = find(y);
}

bool cmp(int x, int y) {
	return abs(w-ed[x].first) < abs(w-ed[y].first);
}

int main() {
	ios::sync_with_stdio(false);
	cin >> n >> m;
	for(int i=0; i<m; i++) {
		cin >> ed[i].second.first >> ed[i].second.second >> ed[i].first;
	}
	sort(ed, ed+m);
	for(int i=1; i<=m; i++) {
		for(int j=1; j<=n; j++) dsu[j] = j;
		used[i].push_back(i-1);
		merge(ed[i-1].second.first, ed[i-1].second.second);
		for(int j:used[i-1]) {
			if(find(ed[j].second.first) != find(ed[j].second.second)) {
				merge(ed[j].second.first, ed[j].second.second);
				used[i].push_back(j);
			}
		}
	}
	for(int i=m-1; i>=0; i--) {
		for(int j=1; j<=n; j++) dsu[j] = j;
		used2[i].push_back(i);
		merge(ed[i].second.first, ed[i].second.second);
		for(int j:used2[i+1]) {
			if(find(ed[j].second.first) != find(ed[j].second.second)) {
				merge(ed[j].second.first, ed[j].second.second);
				used2[i].push_back(j);
			}
		}
	}
	for(int i=0; i<=m; i++) {
		for(int j:used[i]) v[i].push_back(j);
		for(int j:used2[i]) v[i].push_back(j);
	}
	cin >> q;
	while(q--) {
		cin >> w;
		int pos = upper_bound(ed, ed+m, make_pair(w, make_pair((int)1e9, (int)1e9))) - ed;
		sort(v[pos].begin(), v[pos].end(), cmp);
		for(int i=1; i<=n; i++) dsu[i] = i;
		long long ans = 0;
		for(int i:v[pos]) {
			if(find(ed[i].second.first) != find(ed[i].second.second)) {
				ans += abs(w-ed[i].first);
				merge(ed[i].second.first, ed[i].second.second);
			}
		}
		cout << ans << "\n";
	}
} 

• Subtask 1: 3 / 3
• Subtask 2: 4 / 4
• Subtask 3: 0 / 7
• Subtask 4: 0 / 28
• Subtask 5: 0 / 35
• Subtask 6: 0 / 23