제출 #58390

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
58390		ngkan146	코끼리 (Dancing Elephants) (IOI11_elephants)	C++11	97 / 100	9034 ms	9208 KiB

elephants

#include "elephants.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;
const int maxBlockLen = 400;
int n, length;

int numBlock;
vector <int> block[400];
ii startFromThis[400][800];	// [blockId][position] = {last position, how many jumps}

int elephantPos[150005], elephantBLock[150005];

void reBuild(int blockId){
	//~ sort(block[blockId].begin(), block[blockId].end());
	// assuming sorted
	
	for(int i = block[blockId].size()-1;i >= 0; i--){
		int nextPos = upper_bound(block[blockId].begin(), block[blockId].end(), block[blockId][i] + length) - block[blockId].begin();
		if (nextPos == block[blockId].size())
			startFromThis[blockId][i] = {block[blockId][i], 0};
		else
			startFromThis[blockId][i] = startFromThis[blockId][nextPos],
			startFromThis[blockId][i].second ++;
	}
}

void reBuildFull(){
	for(int i=1;i<=numBlock;i++)	block[i].clear();
	numBlock = 1;
	vector <int> lst;
	for(int i=0;i<n;i++)	lst.push_back(i);
	
	sort(lst.begin(), lst.end(), [&](int x,int y){
		return elephantPos[x] < elephantPos[y];
	});
	
	for(int i=0;i<n;i++){
		if (block[numBlock].size() == maxBlockLen)
			++ numBlock;
			
		block[numBlock].push_back(elephantPos[lst[i]]);
		elephantBLock[lst[i]] = numBlock;
	}
	
	for(int i=1;i<=numBlock;i++){
		reBuild(i);
	}
}

int cntUpdTimes;
int update(int elephantId, int newPos){
	if (++cntUpdTimes % 380 == 0)
		reBuildFull();
	//~ cout << "turn " << cntUpdTimes << endl;
	
	block[elephantBLock[elephantId]].erase(
		find(block[elephantBLock[elephantId]].begin(),
			 block[elephantBLock[elephantId]].end(),
			 elephantPos[elephantId]));
		
	reBuild(elephantBLock[elephantId]);
	
	elephantPos[elephantId] = newPos;
	for(int i=1;i<=numBlock;i++){
		if (i == numBlock || newPos <= block[i].back()){
			// block[i].empty() only occur when i = numBlock
			
			elephantBLock[elephantId] = i;
			
			for(int j=0;j<=(int)block[i].size();j++){
				if (j == block[i].size() || newPos <= block[i][j]){
					block[i].insert(block[i].begin() + j, newPos);
					break;
				}
			}
			
			reBuild(i);
			break;
		}
	}
	
	// find res
	int res = 0;
	int last = (int)-(1e9+5);
	for(int i=1;i<=numBlock;i++){
		int startHere = upper_bound(block[i].begin(), block[i].end(), last + length) - block[i].begin();
		if (startHere == block[i].size())	continue;
		res += startFromThis[i][startHere].second + 1;
		last = startFromThis[i][startHere].first;
		//~ cout << startHere << endl;
		//~ for(auto v: block[i])	cout << v << ' '; cout << endl;
	}
	return res;
}

void init(int N, int L, int X[]){
	n = N;
	length = L;
	for(int i=0;i<N;i++){
		elephantPos[i] = X[i];
	}
	reBuildFull();
}

컴파일 시 표준 에러 (stderr) 메시지

elephants.cpp: In function 'void reBuild(int)':
elephants.cpp:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (nextPos == block[blockId].size())
       ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
elephants.cpp: In function 'int update(int, int)':
elephants.cpp:72:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (j == block[i].size() || newPos <= block[i][j]){
         ~~^~~~~~~~~~~~~~~~~~
elephants.cpp:88:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (startHere == block[i].size()) continue;
       ~~~~~~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 24 / 24
• Subtask 4: 47 / 47
• Subtask 5: 0 / 3