Submission #211917

#	Time	Username	Problem	Language	Result	Execution time	Memory
211917		Lawliet	Regions (IOI09_regions)	C++17	95 / 100	8020 ms	90936 KiB

regions

#include <bits/stdc++.h>

using namespace std;
typedef long long int lli;
typedef pair<int,int> pii;

const int MAXN = 200010;

int n, r, q;
int curTime;

int v[MAXN];

int tin[MAXN];
int tout[MAXN];
int prof[MAXN];

int indHeavy[MAXN];
int upAnswer[MAXN];

bool isHeavy[MAXN];

vector< int > adj[MAXN];
vector< int > nodes[MAXN];
vector< int > nodesTin[MAXN];
vector< int > ansHeavy[MAXN];

void DFSInit(int cur)
{
	tin[cur] = ++curTime;

	for(int i = 0 ; i < adj[cur].size() ; i++)
		DFSInit( adj[cur][i] );

	tout[cur] = curTime;
}

void DFSCalculate(int cur, int heavyRegion)
{
	if( v[cur] == heavyRegion )
		prof[cur]++;

	for(int i = 0 ; i < adj[cur].size() ; i++)
	{
		int viz = adj[cur][i];
		
		prof[viz] = prof[cur];

		DFSCalculate( viz , heavyRegion );
	}
}

int lightQuery(int A, int B)
{
	int ans = 0;

	for(int i = 0 ; i < nodes[A].size() ; i++)
	{
		int L = tin[ nodes[A][i] ];
		int R = tout[ nodes[A][i] ];

		auto itL = lower_bound( nodesTin[B].begin() , nodesTin[B].end() , L );
		auto itR = upper_bound( nodesTin[B].begin() , nodesTin[B].end() , R );

		ans += itR - itL;
	}

	return ans;
}

int main()
{
	scanf("%d %d %d",&n,&r,&q);

	int T = sqrt( 2*r ) + 1;

	scanf("%d",&v[1]);

	for(int i = 2 ; i <= n ; i++)
	{
		int p;
		scanf("%d %d",&p,&v[i]);

		adj[p].push_back( i );
	}

	DFSInit( 1 );

	for(int i = 1 ; i <= n ; i++)
	{
		nodes[ v[i] ].push_back( i );
		nodesTin[ v[i] ].push_back( tin[i] );
	}

	for(int i = 1 ; i <= r ; i++)
		sort( nodesTin[i].begin() , nodesTin[i].end() );

	int curInd = 0;

	for(int i = 1 ; i <= r ; i++)
	{
		if( nodes[i].size() < T ) continue;

		isHeavy[i] = true;
		indHeavy[i] = ++curInd;

		prof[1] = 0;
		DFSCalculate( 1 , i );

		for(int j = 1 ; j <= n ; j++)
			upAnswer[ v[j] ] += prof[j];

		for(int j = 1 ; j <= r ; j++)
			ansHeavy[curInd].push_back( upAnswer[j] );

		for(int j = 1 ; j <= r ; j++)
			upAnswer[j] = 0;
	}

	for(int i = 1 ; i <= q ; i++)
	{
		int A, B;
		scanf("%d %d",&A,&B);

		if( !isHeavy[A] ) printf("%d\n",lightQuery( A , B ));
		else
		{
			int ind = indHeavy[A];
			printf("%d\n",ansHeavy[ind][B - 1]);
		}

		fflush( stdout );
	}
}

Compilation message (stderr)

regions.cpp: In function 'void DFSInit(int)':
regions.cpp:32:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0 ; i < adj[cur].size() ; i++)
                  ~~^~~~~~~~~~~~~~~~~
regions.cpp: In function 'void DFSCalculate(int, int)':
regions.cpp:43:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0 ; i < adj[cur].size() ; i++)
                  ~~^~~~~~~~~~~~~~~~~
regions.cpp: In function 'int lightQuery(int, int)':
regions.cpp:57:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0 ; i < nodes[A].size() ; i++)
                  ~~^~~~~~~~~~~~~~~~~
regions.cpp: In function 'int main()':
regions.cpp:102:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if( nodes[i].size() < T ) continue;
       ~~~~~~~~~~~~~~~~^~~
regions.cpp:73:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d",&n,&r,&q);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:77:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&v[1]);
  ~~~~~^~~~~~~~~~~~
regions.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&p,&v[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~
regions.cpp:123:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&A,&B);
   ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 80 / 85