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Submission #1091247

# Submission time Handle Problem Language Result Execution time Memory
1091247 2024-09-20T08:50:38 Z MinhTuan11 Firefighting (NOI20_firefighting) C++17
55 / 100
 263 ms 62732 KB 
#include <bits/stdc++.h>

#define int long long
#define fi first
#define se second

const int N = 3e5 + 5;
const int K = 1e2 + 5;
const int mod = 1e9 + 7;
const int inf = 1e18;

#define all(v) (v).begin(), (v).end()
#define pii pair<int, int> 

using namespace std;

mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

int n, f, h[N];
vector<pii> adj[N];
vector<int> pos;
int g[N], b[N], l, r, mid, cnt;

void pre(int u, int p) {
	for(pii w : adj[u]) {
		int v = w.fi, c = w.se;
		if(v == p) continue;
		h[v] = c;
		pre(v, u);
	}
}

void dfs(int u, int p) {
	vector<int> a;
	int mini = inf;
	for(pii w : adj[u]) {
		int v = w.fi, c = w.se;
		if(v == p) continue;
		dfs(v, u);
		a.push_back(b[v] + c);
		mini = min(mini, g[v] + c);
	}
	sort(all(a));
	if(a.size() == 0) {
		if(h[u] > mid) {
			// cout << "+ " << u << '\n';
			pos.push_back(u);
			cnt++;
			g[u] = 0;
			b[u] = -h[u];
		}
		else {
			g[u] = inf;
			b[u] = 0;
		}
		return;
	}
	if(u == 1) {
		// cout << u << ' ' << a.back() << ' ' << mini << '\n';
		if(mini > mid) {
			// cout << "+ " << u << '\n';
			pos.push_back(u);
			cnt++;
			return;
		}
		else {
			if(a.back() + mini > mid) {
				// cout << "+ " << u << '\n';
				pos.push_back(u);
				cnt++;
				return;
			}
		}
	}
	if(a[0] > mid) {
		if(h[u] > mid) {
			// cout << "+ " << u << '\n';
			pos.push_back(u);
			cnt++;
			g[u] = 0;
			b[u] = -h[u];
		}
		else {
			g[u] = inf;
			b[u] = 0;
		}
		return;
	}
	if(mini > mid) {
		// cout << u << ' ' << a.back() << ' ' << mini << '\n';
		if(a.back() + h[u] > mid) {
			// cout << "+ " << u << '\n';
			pos.push_back(u);
			cnt++;
			g[u] = 0;
			b[u] = -h[u];
		}
		else {
			g[u] = mini;
			b[u] = a.back();
		}
	}
	else {
		// cout << u << ' ' << a.back() << ' ' << mini << '\n';
		if(a.back() + h[u] > mid) {
			if(a.back() + mini > mid) {
				// cout << "+ " << u << '\n';
				pos.push_back(u);
				cnt++;
				g[u] = 0;
				b[u] = -h[u];
			}
			else {
				g[u] = mini;
				b[u] = 0;
			}
		}
		else {
			g[u] = mini;
			b[u] = a.back();
			if(a.back() + mini <= mid) b[u] = -h[u];
		}
	}
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    if(ifstream("file.inp")){
    	freopen("file.inp", "r", stdin);
    	freopen("file.out", "w", stdout);
    }
    
    cin >> n >> f;
    for(int i = 2; i <= n; i++) {
    	int j, t;
    	int x;
    	cin >> x;
    	cin >> j >> t;
    	adj[x].push_back({j, t});
    	adj[j].push_back({x, t});
    	r += t;
    	// cout << i << ' ' << j << ' ' << t << '\n';
    }
    mid = f;
    pre(1, 0);
    dfs(1, 0);
    // l = 3, r = 3;
    // int res = inf;
    // while(l <= r) {
    	// mid = l + r >> 1;
    	// cnt = 0;
    	// for(int i = 1; i <= n; i++) {
    		// g[i] = inf;
    	// }
    	// dfs(1, 0);
    	// // cout << "cnt: " << cnt << '\n';
    	// if(cnt <= f) {
    		// res = mid;
    		// r = mid - 1;
    	// }
    	// else l = mid + 1;
    // }
    // cout << res << '\n';
    if(cnt == 0) {
    	cnt++;
    	pos.push_back(1);
    }
    cout << cnt << '\n';
    for(int x : pos) cout << x << ' ';
    
    return 0;
}

// tuntun

Compilation message

Firefighting.cpp: In function 'int main()':
Firefighting.cpp:131:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |      freopen("file.inp", "r", stdin);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Firefighting.cpp:132:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  132 |      freopen("file.out", "w", stdout);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 214 ms 41656 KB Output is correct
2 Correct 232 ms 41660 KB Output is correct
3 Correct 64 ms 20168 KB Output is correct
4 Correct 212 ms 40900 KB Output is correct
5 Correct 3 ms 7512 KB Output is correct
6 Correct 4 ms 7516 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 7516 KB Output is correct
2 Correct 4 ms 7516 KB Output is correct
3 Correct 4 ms 7512 KB Output is correct
4 Correct 4 ms 7516 KB Output is correct
5 Correct 3 ms 7468 KB Output is correct
6 Correct 3 ms 7516 KB Output is correct
7 Correct 3 ms 7300 KB Output is correct
8 Correct 3 ms 7516 KB Output is correct
9 Correct 3 ms 7516 KB Output is correct
10 Correct 3 ms 7516 KB Output is correct
11 Correct 3 ms 7516 KB Output is correct
12 Correct 3 ms 7288 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 3 ms 7516 KB Output is correct
15 Correct 4 ms 7516 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 7516 KB Output is correct
2 Correct 3 ms 7516 KB Output is correct
3 Correct 3 ms 7516 KB Output is correct
4 Correct 3 ms 7516 KB Output is correct
5 Correct 4 ms 7448 KB Output is correct
6 Correct 3 ms 7292 KB Output is correct
7 Correct 4 ms 7512 KB Output is correct
8 Correct 3 ms 7512 KB Output is correct
9 Correct 4 ms 7516 KB Output is correct
10 Correct 4 ms 7512 KB Output is correct
11 Correct 4 ms 7516 KB Output is correct
12 Correct 3 ms 7516 KB Output is correct
13 Correct 4 ms 7516 KB Output is correct
14 Correct 3 ms 7516 KB Output is correct
15 Correct 3 ms 7516 KB Output is correct
16 Correct 3 ms 7516 KB Output is correct
17 Correct 3 ms 7516 KB Output is correct
18 Correct 4 ms 7516 KB Output is correct
19 Correct 3 ms 7516 KB Output is correct
20 Correct 3 ms 7516 KB Output is correct
21 Correct 3 ms 7516 KB Output is correct
22 Correct 3 ms 7516 KB Output is correct
23 Correct 4 ms 7512 KB Output is correct
24 Correct 6 ms 7460 KB Output is correct
25 Correct 4 ms 7516 KB Output is correct
26 Correct 3 ms 7516 KB Output is correct

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 42012 KB Output is correct
2 Correct 93 ms 24524 KB Output is correct
3 Correct 93 ms 24776 KB Output is correct
4 Correct 75 ms 22472 KB Output is correct
5 Correct 3 ms 7512 KB Output is correct
6 Correct 3 ms 7516 KB Output is correct
7 Correct 175 ms 39352 KB Output is correct
8 Correct 168 ms 40464 KB Output is correct
9 Correct 174 ms 39604 KB Output is correct
10 Correct 176 ms 39400 KB Output is correct
11 Correct 220 ms 41920 KB Output is correct
12 Incorrect 106 ms 28516 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 7768 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 203 ms 36432 KB Output is correct
2 Correct 172 ms 34896 KB Output is correct
3 Correct 199 ms 37068 KB Output is correct
4 Correct 91 ms 21232 KB Output is correct
5 Correct 246 ms 54604 KB Output is correct
6 Correct 251 ms 52140 KB Output is correct
7 Correct 249 ms 59316 KB Output is correct
8 Correct 229 ms 57296 KB Output is correct
9 Correct 233 ms 49012 KB Output is correct
10 Correct 263 ms 47640 KB Output is correct
11 Correct 249 ms 62732 KB Output is correct
12 Correct 119 ms 27384 KB Output is correct
13 Correct 234 ms 51300 KB Output is correct
14 Correct 226 ms 45680 KB Output is correct
15 Correct 217 ms 37440 KB Output is correct
16 Correct 176 ms 35408 KB Output is correct
17 Correct 190 ms 35132 KB Output is correct
18 Correct 205 ms 37200 KB Output is correct
19 Correct 103 ms 28244 KB Output is correct
20 Correct 56 ms 19156 KB Output is correct
21 Correct 174 ms 37204 KB Output is correct