Submission #544926

#	Time	Username	Problem	Language	Result	Execution time	Memory
544926		benson1029	Reconstruction Project (JOI22_reconstruction)	C++14	3 / 100	5083 ms	818200 KiB

reconstruction

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

int n, m, q;
pair< int, pair<int,int> > edg[100005];
vector<int> f[100005], b[100005], t[100005];
int x[100005], y[100005];
int dsu[100005];

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

void merge(int x) {
	dsu[find(edg[x].second.first)] = find(edg[x].second.second);
}

bool ok(int p, int v) {
	return ((x[p]==-1 || v>=x[p]) && (y[p]==-1 || v<=y[p]));
}

int main() {
	ios::sync_with_stdio(false);
	cin >> n >> m;
	for(int i=1; i<=m; i++) {
		cin >> edg[i].second.first >> edg[i].second.second >> edg[i].first;
	}
	sort(edg+1, edg+m+1);
	for(int i=1; i<=m; i++) {
		b[i].push_back(i);
		for(int j=1; j<=n; j++) dsu[j] = j;
		merge(i);
		for(int j:b[i-1]) {
			if(find(edg[j].second.first)!=find(edg[j].second.second)) {
				merge(j);
				b[i].push_back(j);
			}
		}
		for(int j=1; j<=n; j++) dsu[j] = j;
		x[i] = -1;
		for(int j:b[i-1]) {
			merge(j);
			if(find(edg[i].second.first)==find(edg[i].second.second)) {
				x[i] = (edg[j].first + edg[i].first + 1) / 2;
				break;
			}
		}
	}
	for(int i=m; i>=1; i--) {
		f[i].push_back(i);
		for(int j=1; j<=n; j++) dsu[j] = j;
		merge(i);
		for(int j:f[i+1]) {
			if(find(edg[j].second.first)!=find(edg[j].second.second)) {
				merge(j);
				f[i].push_back(j);
			}
		}
		for(int j=1; j<=n; j++) dsu[j] = j;
		y[i] = -1;
		for(int j:f[i+1]) {
			merge(j);
			if(find(edg[i].second.first)==find(edg[i].second.second)) {
				y[i] = (edg[j].first + edg[i].first) / 2; 
				break;
			}
		}
	}
	for(int i=0; i<=m; i++) {
		for(int j:b[i]) t[i].push_back(j);
		for(int j:f[i+1]) t[i].push_back(j);
	}
	cin >> q;
	while(q--) {
		int v;
		cin >> v;
		int pos = upper_bound(edg+1, edg+m+1, make_pair(v, make_pair((int)1e9, (int)1e9))) - edg - 1;
		for(int i=1; i<=n; i++) dsu[i] = i;
		long long ans = 0;
		for(int i:t[pos]) {
			if(find(edg[i].second.first)!=find(edg[i].second.second) && ok(i, v)) {
				merge(i);
				ans += abs(v-edg[i].first);
			}
		}
		cout << ans << "\n";
	}
}

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