oj.uz

Submission #535507

# Submission time Handle Problem Language Result Execution time Memory
535507 2022-03-10T12:02:12 Z Asymmetry Mousetrap (CEOI17_mousetrap) C++17
45 / 100
 980 ms 64056 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;
}

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];
	}
	cost[x] = 0;
	while (x != m) {
		x = son[x];
		blk[x] = blk[par[x]];
		vector<int> war = {0, 0};
		for (int i : v[x]) {
			if (i != par[x] && i != son[x]) {
				war.push_back(dp[i]);
				++blk[x];
			}
		}
		nth_element(war.begin(), war.begin() + 1, war.end(), [&](int a, int b) {
			return a > b;
		});
		cost[x] = max(war[1] + blk[x], cost[x]);
	}
	//~ for (int i = 1; i <= n; ++i) {
		//~ printf("%d: %d\n", i, dp[i]);
	//~ }
	printf("%d\n", cost[m]);
	return 0;
}

Compilation message

mousetrap.cpp: In function 'int main()':
mousetrap.cpp:38:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |  scanf("%d%d%d", &n, &q, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:40:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |   scanf("%d%d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23764 KB Output is correct
2 Correct 15 ms 23752 KB Output is correct
3 Correct 13 ms 23764 KB Output is correct
4 Correct 14 ms 23764 KB Output is correct
5 Correct 15 ms 23784 KB Output is correct
6 Correct 16 ms 23892 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23820 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 12 ms 23776 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 431 ms 62864 KB Output is correct
2 Correct 362 ms 59068 KB Output is correct
3 Correct 980 ms 64040 KB Output is correct
4 Correct 432 ms 43852 KB Output is correct
5 Correct 907 ms 63964 KB Output is correct
6 Correct 865 ms 64056 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23764 KB Output is correct
2 Correct 15 ms 23752 KB Output is correct
3 Correct 13 ms 23764 KB Output is correct
4 Correct 14 ms 23764 KB Output is correct
5 Correct 15 ms 23784 KB Output is correct
6 Correct 16 ms 23892 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23820 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 12 ms 23776 KB Output is correct
11 Incorrect 13 ms 23764 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23764 KB Output is correct
2 Correct 15 ms 23752 KB Output is correct
3 Correct 13 ms 23764 KB Output is correct
4 Correct 14 ms 23764 KB Output is correct
5 Correct 15 ms 23784 KB Output is correct
6 Correct 16 ms 23892 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23820 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 12 ms 23776 KB Output is correct
11 Correct 431 ms 62864 KB Output is correct
12 Correct 362 ms 59068 KB Output is correct
13 Correct 980 ms 64040 KB Output is correct
14 Correct 432 ms 43852 KB Output is correct
15 Correct 907 ms 63964 KB Output is correct
16 Correct 865 ms 64056 KB Output is correct
17 Incorrect 13 ms 23764 KB Output isn't correct
18 Halted 0 ms 0 KB -