oj.uz

Submission #106310

# Submission time Handle Problem Language Result Execution time Memory
106310 2019-04-17T20:54:45 Z RedNextCentury Ball Machine (BOI13_ballmachine) C++14
100 / 100
 288 ms 19480 KB 
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <set>
#include <queue>
#include <utility>
using namespace std;

// full solution
// (author: simon buerger)

void readTree(int n, vector<int>& nodes)
{
	nodes.resize(n);
	for(int i = 0; i < n; ++i)
	{
		scanf("%d", &nodes[i]);
		nodes[i]--;
		if(nodes[i] == -1)
			nodes[i] = i;
	}
}

#define LOGN 17	// will work for n <= 100.000
int n, q;
vector<int> par[LOGN];
vector<vector<int> > g;
vector<int> low;
vector<int> post;
vector<bool> ball;
vector<int> layer;	// root is at 0
int root;
bool cmpLow(int a, int b) { return low[a] < low[b]; }
bool cmpPostInv(int a, int b) { return post[a] > post[b]; }
priority_queue<int, vector<int>, bool(*)(int,int)> empty(cmpPostInv);
vector<int> full;	// not ordered in any sense

void dfsLow(int v)
{
	if(v == root)
		layer[v] = 0;
	else
		layer[v] = 1 + layer[par[0][v]];

	low[v] = v;
	for(int i = 0; i < (int)g[v].size(); ++i)
	{
		int w = g[v][i];
		dfsLow(w);
		low[v] = min(low[v], low[w]);
	}
}

void dfsPost(int v)
{
	static int time = 0;
	for(int i = 0; i < (int)g[v].size(); ++i)
		dfsPost(g[v][i]);
	post[v] = time++;
}

int add()	// return pos
{
	int k = empty.top();
	empty.pop();
	ball[k] = true;
	return k;
}

int remove(int pos)	// return position of actual remove
{
	if(!ball[pos])
		cerr << "ERROR: remove from empty node" << endl;
	//cerr << "remove " << pos;
	for(int level = LOGN-1; level >= 0; --level)
		if(ball[par[level][pos]])
			pos = par[level][pos];

	ball[pos] = false;
	empty.push(pos);
	//cerr << " actual = " << pos << endl;
	return pos;
}

int main(int argc, char** argv)
{
	scanf("%d %d", &n, &q);

	g.resize(n);
	for(int i = 0; i < LOGN; ++i)
		par[i].resize(n);
	ball.resize(n, false);
	low.resize(n);
	post.resize(n);
	layer.resize(n);

	readTree(n, par[0]);

	for(int i = 0; i < n; ++i)
		if(par[0][i] == i)
			root = i;
		else
			g[par[0][i]].push_back(i);

	par[0][root] = root;
	for(int level = 1; level < LOGN; ++level)
		for(int i = 0; i < n; ++i)
			par[level][i] = par[level-1][par[level-1][i]];

	dfsLow(root);
	for(int i = 0; i < n; ++i)
		sort(g[i].begin(), g[i].end(), cmpLow);

	dfsPost(root);
	for(int i = 0; i < n; ++i)
		empty.push(i);

	for(int i = 0; i < q; ++i)
	{
		int t, k;
		scanf("%d %d", &t, &k);

		if(t == 1)	// add k balls
		{
			for(int j = 0; j < k; ++j)
			{
				int pos = add();
				if(j+1 == k)
					printf("%d\n", pos+1);
			}
		}
		else if(t == 2)	// remove one ball from position k
		{
			--k;
			int actual = remove(k);
			printf("%d\n", layer[k]-layer[actual]);
		}
		else cerr << "ERROR: invalid t" << endl;
	}
}

Compilation message

ballmachine.cpp: In function 'void readTree(int, std::vector<int>&)':
ballmachine.cpp:18:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &nodes[i]);
   ~~~~~^~~~~~~~~~~~~~~~~
ballmachine.cpp: In function 'int main(int, char**)':
ballmachine.cpp:88:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &q);
  ~~~~~^~~~~~~~~~~~~~~~~
ballmachine.cpp:122:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &t, &k);
   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 168 ms 8680 KB Output is correct
3 Correct 68 ms 8952 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 3 ms 512 KB Output is correct
8 Correct 3 ms 512 KB Output is correct
9 Correct 7 ms 896 KB Output is correct
10 Correct 20 ms 2492 KB Output is correct
11 Correct 133 ms 8652 KB Output is correct
12 Correct 80 ms 8952 KB Output is correct
13 Correct 121 ms 8852 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 4088 KB Output is correct
2 Correct 177 ms 15608 KB Output is correct
3 Correct 82 ms 12788 KB Output is correct
4 Correct 59 ms 5120 KB Output is correct
5 Correct 59 ms 4992 KB Output is correct
6 Correct 59 ms 5084 KB Output is correct
7 Correct 59 ms 4344 KB Output is correct
8 Correct 38 ms 4088 KB Output is correct
9 Correct 161 ms 15984 KB Output is correct
10 Correct 179 ms 15696 KB Output is correct
11 Correct 136 ms 15580 KB Output is correct
12 Correct 169 ms 14168 KB Output is correct
13 Correct 140 ms 17136 KB Output is correct
14 Correct 84 ms 12816 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 79 ms 8312 KB Output is correct
2 Correct 192 ms 14476 KB Output is correct
3 Correct 190 ms 15724 KB Output is correct
4 Correct 153 ms 13120 KB Output is correct
5 Correct 140 ms 12716 KB Output is correct
6 Correct 145 ms 12632 KB Output is correct
7 Correct 133 ms 11768 KB Output is correct
8 Correct 156 ms 15624 KB Output is correct
9 Correct 225 ms 16084 KB Output is correct
10 Correct 211 ms 15984 KB Output is correct
11 Correct 212 ms 15856 KB Output is correct
12 Correct 217 ms 14584 KB Output is correct
13 Correct 288 ms 19480 KB Output is correct
14 Correct 159 ms 12776 KB Output is correct

Subtask #4
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 235 ms 16212 KB Output is correct
2 Correct 242 ms 14568 KB Output is correct
3 Correct 142 ms 19320 KB Output is correct
4 Correct 231 ms 16240 KB Output is correct
5 Correct 209 ms 15872 KB Output is correct
6 Correct 185 ms 15880 KB Output is correct
7 Correct 192 ms 14580 KB Output is correct
8 Correct 126 ms 19344 KB Output is correct
9 Correct 95 ms 12788 KB Output is correct