oj.uz

Submission #1092190

# Submission time Handle Problem Language Result Execution time Memory
1092190 2024-09-23T13:37:53 Z MinhTuan11 Firefighting (NOI20_firefighting) C++17
36 / 100
 189 ms 41656 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) {
	// cout << u << '\n';
	vector<int> a;
	int mini = inf;
	for(pii w : adj[u]) {
		int v = w.fi, c = w.se;
		if(c > mid) continue;
		if(v == p) continue;
		dfs(v, u);
		// cout << v << ' ' << b[v] << '\n';
		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 || h[u] > mid) {
		// cout << u << ' ' << a.back() << ' ' << mini << '\n';
		if(mini > mid) {
			// cout << "+ " << u << '\n';
			pos.push_back(u);
			cnt++;
			return;
		}
		else {
			// cout << a.back() << '\n';
			if(a.back() + mini > mid) {
				// cout << "+ " << u << '\n';
				pos.push_back(u);
				cnt++;
				return;
			}
		}
		return;
	}
	// if(h[u] > mid) {
		// if(mini > mid) {
			// pos.push_back(u);
			// cnt++;
			// g[u] = 0;
			// b[u] = -h[u];
		// }
		// else {
			// g[u] = mini;
			// b[u] = 0;
		// }
		// return;
	// }
	// if(a[0] > mid) {
		// cout << u << '\n';
		// //assert(1 == 2);
		// // 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] = a.back();
			}
		}
		else {
			g[u] = mini;
			b[u] = a.back();
			if(a.back() + mini <= mid) b[u] = -h[u];
		}
	}
}
 
namespace checker {
	bool check() {
		priority_queue<pii, vector<pii>, greater<pii>> q;
		vector<int> d(n + 1, inf);
		for(int x : pos) {
			q.push({0, x});
			d[x] = 0;
		}
		while(q.size()) {
			int y = q.top().se;
			int dy = q.top().fi;
			q.pop();
			if(dy > d[y]) continue;
			if(dy > mid) return 0;
			// cout << y << ' ' << d[y] << '\n';
			for(pii z : adj[y]) {
				if(d[z.fi] > d[y] + z.se) {
					d[z.fi] = d[y] + z.se;
					q.push({d[z.fi], z.fi});
				}
			}
		}
		return 1;
	}
}
 
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);
    for(int i = 1; i <= n; i++) {
    	int pcnt = cnt;
    	if(i == 1 || h[i] > mid) {
    		dfs(i, 0);
    		if(cnt == pcnt) {
    			cnt++;
    			pos.push_back(i);
    		}
    	}
    }
    // 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);
    // }
    // if(!checker::check()) {
    	// assert(1 == 2);
    // }
    cout << cnt << '\n';
    for(int x : pos) cout << x << ' ';
    
    return 0;
}
 
// tuntun

Compilation message

Firefighting.cpp: In function 'int main()':
Firefighting.cpp:177:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  177 |      freopen("file.inp", "r", stdin);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Firefighting.cpp:178:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  178 |      freopen("file.out", "w", stdout);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 159 ms 41656 KB Output is correct
2 Correct 150 ms 41648 KB Output is correct
3 Correct 51 ms 19976 KB Output is correct
4 Correct 143 ms 40548 KB Output is correct
5 Correct 3 ms 7512 KB Output is correct
6 Correct 3 ms 7512 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 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 3 ms 7516 KB Output is correct
6 Correct 5 ms 7532 KB Output is correct
7 Correct 3 ms 7488 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 7432 KB Output is correct
12 Correct 3 ms 7492 KB Output is correct
13 Correct 3 ms 7516 KB Output is correct
14 Correct 3 ms 7516 KB Output is correct
15 Correct 3 ms 7516 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7516 KB Output is correct
2 Correct 4 ms 7512 KB Output is correct
3 Correct 3 ms 7516 KB Output is correct
4 Correct 3 ms 7516 KB Output is correct
5 Correct 3 ms 7396 KB Output is correct
6 Correct 4 ms 7512 KB Output is correct
7 Correct 3 ms 7516 KB Output is correct
8 Correct 3 ms 7464 KB Output is correct
9 Correct 5 ms 7516 KB Output is correct
10 Correct 4 ms 7512 KB Output is correct
11 Correct 3 ms 7516 KB Output is correct
12 Correct 3 ms 7516 KB Output is correct
13 Correct 3 ms 7512 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 7356 KB Output is correct
18 Correct 3 ms 7516 KB Output is correct
19 Correct 3 ms 7512 KB Output is correct
20 Correct 3 ms 7512 KB Output is correct
21 Correct 3 ms 7516 KB Output is correct
22 Correct 3 ms 7512 KB Output is correct
23 Correct 3 ms 7528 KB Output is correct
24 Correct 3 ms 7516 KB Output is correct
25 Correct 3 ms 7468 KB Output is correct
26 Correct 3 ms 7516 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 157 ms 41536 KB Output is correct
2 Correct 95 ms 24528 KB Output is correct
3 Correct 84 ms 24768 KB Output is correct
4 Correct 76 ms 22476 KB Output is correct
5 Correct 4 ms 7512 KB Output is correct
6 Correct 3 ms 7516 KB Output is correct
7 Correct 162 ms 39352 KB Output is correct
8 Correct 149 ms 40628 KB Output is correct
9 Correct 160 ms 39516 KB Output is correct
10 Correct 154 ms 39552 KB Output is correct
11 Correct 154 ms 41528 KB Output is correct
12 Correct 91 ms 28360 KB Output is correct
13 Correct 62 ms 20428 KB Output is correct
14 Correct 87 ms 27076 KB Output is correct
15 Correct 112 ms 31176 KB Output is correct
16 Correct 125 ms 32976 KB Output is correct
17 Correct 101 ms 28924 KB Output is correct
18 Correct 98 ms 28484 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 7772 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 38.0

# Verdict Execution time Memory Grader output
1 Incorrect 189 ms 36432 KB Output isn't correct
2 Halted 0 ms 0 KB -