oj.uz

Submission #541907

# Submission time Handle Problem Language Result Execution time Memory
541907 2022-03-24T18:54:45 Z Asymmetry Mousetrap (CEOI17_mousetrap) C++17
65 / 100
 844 ms 211584 KB 
//Autor: Bartłomiej Czarkowski
#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';}
template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';}
#define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...);}(x),cerr<<'\n'
#else
#define debug(...) {}
#endif

const int N = 1001000;
int n, a, b, m, q;
int par[N];
int son[N];
int cost[N];
int blk[N];
int dp[N]; // ile żeby uwięzić i wyprowadzić do ojca
vector<int> v[N];

void dfs_dp(int x) {
	vector<int> war = {0, 0};
	for (int i : v[x]) {
		if (i == par[x]) {
			continue;
		}
		par[i] = x;
		dfs_dp(i);
		war.push_back(dp[i]);
	}
	nth_element(war.begin(), war.begin() + 1, war.end(), [&](int a, int b) {
		return a > b;
	});
	dp[x] = war[1] + war.size() - 2;
}

bool check(int wyn) {
	int x = m, nad = 1, usd = 0;
	while (x != q) {
		int ile = 0;
		for (int i : v[x]) {
			if (i != par[x] && i != son[x]) {
				if (dp[i] + blk[x] + usd > wyn) {
					++ile;
				}
			}
		}
		if (ile > nad) {
			return false;
		}
		nad -= ile;
		usd += ile;
		x = par[x];
		++nad;
	}
	return usd <= wyn;
}

int main() {
	scanf("%d%d%d", &n, &q, &m);
	for (int i = 1; i < n; ++i) {
		scanf("%d%d", &a, &b);
		v[a].push_back(b);
		v[b].push_back(a);
	}
	dfs_dp(q);
	int x = m;
	while (x != q) {
		son[par[x]] = x;
		x = par[x];
	}
	while (x != m) {
		x = son[x];
		blk[x] = blk[par[x]];
		for (int i : v[x]) {
			blk[x] += (i != par[x]) && (i != son[x]);
		}
	}
	int bp = -1, bk = min(n, 1000), bs;
	while (bk - bp > 1) {
		bs = (bp + bk) / 2;
		if (check(bs)) {
			bk = bs;
		}
		else {
			bp = bs;
		}
	}
	printf("%d\n", bk);
	return 0;
}

Compilation message

mousetrap.cpp: In function 'int main()':
mousetrap.cpp:60:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |  scanf("%d%d%d", &n, &q, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:62:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d%d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 23764 KB Output is correct
3 Correct 12 ms 23808 KB Output is correct
4 Correct 11 ms 23820 KB Output is correct
5 Correct 11 ms 23764 KB Output is correct
6 Correct 12 ms 23764 KB Output is correct
7 Correct 12 ms 23836 KB Output is correct
8 Correct 11 ms 23784 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 11 ms 23764 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 343 ms 62844 KB Output is correct
2 Correct 338 ms 59032 KB Output is correct
3 Correct 814 ms 64192 KB Output is correct
4 Correct 364 ms 44032 KB Output is correct
5 Correct 819 ms 64032 KB Output is correct
6 Correct 822 ms 63944 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 23764 KB Output is correct
3 Correct 12 ms 23808 KB Output is correct
4 Correct 11 ms 23820 KB Output is correct
5 Correct 11 ms 23764 KB Output is correct
6 Correct 12 ms 23764 KB Output is correct
7 Correct 12 ms 23836 KB Output is correct
8 Correct 11 ms 23784 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 11 ms 23764 KB Output is correct
11 Correct 13 ms 23844 KB Output is correct
12 Correct 12 ms 23764 KB Output is correct
13 Correct 12 ms 23808 KB Output is correct
14 Correct 12 ms 24020 KB Output is correct
15 Correct 12 ms 23992 KB Output is correct
16 Correct 12 ms 23828 KB Output is correct
17 Correct 13 ms 23764 KB Output is correct
18 Correct 12 ms 23896 KB Output is correct
19 Correct 13 ms 23892 KB Output is correct
20 Correct 16 ms 23892 KB Output is correct
21 Correct 12 ms 23764 KB Output is correct
22 Correct 13 ms 23872 KB Output is correct

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 23764 KB Output is correct
3 Correct 12 ms 23808 KB Output is correct
4 Correct 11 ms 23820 KB Output is correct
5 Correct 11 ms 23764 KB Output is correct
6 Correct 12 ms 23764 KB Output is correct
7 Correct 12 ms 23836 KB Output is correct
8 Correct 11 ms 23784 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 11 ms 23764 KB Output is correct
11 Correct 343 ms 62844 KB Output is correct
12 Correct 338 ms 59032 KB Output is correct
13 Correct 814 ms 64192 KB Output is correct
14 Correct 364 ms 44032 KB Output is correct
15 Correct 819 ms 64032 KB Output is correct
16 Correct 822 ms 63944 KB Output is correct
17 Correct 13 ms 23844 KB Output is correct
18 Correct 12 ms 23764 KB Output is correct
19 Correct 12 ms 23808 KB Output is correct
20 Correct 12 ms 24020 KB Output is correct
21 Correct 12 ms 23992 KB Output is correct
22 Correct 12 ms 23828 KB Output is correct
23 Correct 13 ms 23764 KB Output is correct
24 Correct 12 ms 23896 KB Output is correct
25 Correct 13 ms 23892 KB Output is correct
26 Correct 16 ms 23892 KB Output is correct
27 Correct 12 ms 23764 KB Output is correct
28 Correct 13 ms 23872 KB Output is correct
29 Correct 12 ms 23844 KB Output is correct
30 Correct 354 ms 62960 KB Output is correct
31 Correct 382 ms 63044 KB Output is correct
32 Correct 495 ms 211584 KB Output is correct
33 Correct 424 ms 203748 KB Output is correct
34 Correct 828 ms 64160 KB Output is correct
35 Correct 844 ms 64120 KB Output is correct
36 Incorrect 820 ms 78864 KB Output isn't correct
37 Halted 0 ms 0 KB -