oj.uz

Submission #262854

# Submission time Handle Problem Language Result Execution time Memory
262854 2020-08-13T10:06:40 Z user202729 Robots (APIO13_robots) C++17
60 / 100
 1500 ms 143992 KB 
// 2
#ifndef LOCAL
#define NDEBUG 1
#endif
#include<bits/stdc++.h>


int numRobot, numRow, numCol;
std::vector<std::vector<char>> data;
struct Pos{
	int row, col;
	int index() const{
		assert((unsigned) row<(unsigned) numRow); assert((unsigned) col<(unsigned) numCol);
		return col+numCol*row;
	}
};
struct State{
	int dir; // dir+1: clockwise
	int row, col;
	std::pair<int, int> dirVector() const{
		std::pair<int, int> result{1, 0};
		switch(dir){
			case 3: result={result.second,-result.first};
			case 2: result={result.second,-result.first};
			case 1: result={result.second,-result.first};
			case 0: return result;
		}
		assert(false);
	}

	int index() const{return dir+4*Pos{row, col}.index();}
};

int const loop=-2, uncomputed=-1;
std::vector<int> memory;

int compute(State it){
	auto& curMemory=memory[it.index()];
	if(curMemory!=uncomputed) return curMemory;

	State next=it;
	switch(data[next.row][next.col]){
		case 'A':
			next.dir=(next.dir-1)&3; break;
		case 'C':
			next.dir=(next.dir+1)&3; break;
		case 'x':
			assert(false); __builtin_unreachable();
	}
	next.row+=next.dirVector().first; next.col+=next.dirVector().second;

	if((unsigned)next.row>=(unsigned)numRow or (unsigned)next.col>=(unsigned)numCol or
			data[next.row][next.col]=='x')
		return curMemory=Pos{it.row, it.col}.index();

	curMemory=loop;
	return curMemory=compute(next);
}

int getMemory(int pos, int dir){
	int result=memory[dir+4*pos];
	assert(result!=uncomputed);
	return result;
}

int main(){
	std::ios::sync_with_stdio(0);std::cin.tie(0);
	std::cin>>numRobot>>numCol>>numRow;
	if(numRobot==1){std::cout<<"0\n"; return 0;}
	data.resize(numRow);
	for(auto& row: data){
		row.resize(numCol+1);
		std::cin>>row.data();
		assert(row.back()==0); row.pop_back();
		assert(row.back()!=0);
	}

	memory.assign(numRow*numCol*4, uncomputed);
	for(int row=0; row<numRow; ++row)
		for(int col=0; col<numCol; ++col)
			if(data[row][col]!='x')
				for(int dir=0; dir<4; ++dir){
					auto const result=compute({dir, row, col});
					(void) result;
					/*
					std::cerr<<row<<' '<<col<<' '<<dir<<'-'
						<<result/numCol<<' '<<result%numCol<<'\n';
						*/
				}

	int const numPos=numRow*numCol;
	std::vector<int> distance_(numPos*numRobot*numRobot, INT_MAX);
	auto const distance=[&](int a, int b, int pos)->int&{
		assert(0<=a); assert(a<=b); assert(b<numRobot);
		assert((unsigned)pos<unsigned(numPos));
		return distance_[a+numRobot*(b+numRobot*pos)];
	};

	std::vector<std::vector<int>> queue(numPos);

	int result=INT_MAX;
	for(int a=numRobot; a--;){
		for(int b=a; b<numRobot; ++b){
			struct State{
				int pos, distance;
				bool operator<(State it) const{return distance>it.distance;}
			};

			int minDistance=INT_MAX, maxDistance=0;
			if(a==b){
				//for(int pos=0; pos<numPos; ++pos)
				for(int row=0; row<numRow; ++row)
					for(int col=0; col<numCol; ++col){
						assert(distance(a, a, Pos{row, col}.index())==INT_MAX);
						if(data[row][col]==char('1'+a)){
							auto const pos=Pos{row, col}.index();
							queue[distance(a, a, pos)=0].push_back(pos);
							minDistance=0;
						}
					}
			}else{
				for(int pos=0; pos<numPos; ++pos){
					unsigned t=INT_MAX;
					for(int m=a; m<b; ++m)
						t=std::min(t, (unsigned)distance(a, m, pos)+
								distance(m+1, b, pos));
					assert(distance(a, b, pos)==INT_MAX);
					if(t<INT_MAX){
						if(b==numRobot-1 and a==0)
							result=std::min(result, (int)t);
						else{
							while(t>=(int)queue.size()) queue.resize(queue.size()*2);
							queue[distance(a, b, pos)=t].push_back(pos);
							minDistance=std::min(minDistance, (int)t);
							maxDistance=std::max(maxDistance, (int)t);
						}
					}
				}
			}

			for(int curDistance=minDistance; curDistance<=maxDistance; ++curDistance){
				for(auto pos: queue[curDistance]){
					if(curDistance!=distance(a, b, pos)) continue;
					for(int dir=0; dir<4; ++dir){
						auto const next=getMemory(pos, dir);
						if(next!=loop and distance(a, b, next)>curDistance+1){
							while(curDistance+1>=(int)queue.size()) queue.resize(queue.size()*2);
							queue[distance(a, b, next)=curDistance+1].push_back(next);
							maxDistance=std::max(maxDistance, curDistance+1);
						}
					}
				}
			}
		}
	}
	std::cout<<(result==INT_MAX ? -1: result)<<'\n';
}

Compilation message

robots.cpp: In function 'int main()':
robots.cpp:132:15: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int' [-Wsign-compare]
  132 |        while(t>=(int)queue.size()) queue.resize(queue.size()*2);
      |              ~^~~~~~~~~~~~~~~~~~~
robots.cpp: In member function 'std::pair<int, int> State::dirVector() const':
robots.cpp:29:2: warning: control reaches end of non-void function [-Wreturn-type]
   29 |  }
      |  ^

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct

Subtask #3
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 227 ms 36984 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 50 ms 21248 KB Output is correct
14 Correct 440 ms 51064 KB Output is correct
15 Correct 158 ms 34436 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 227 ms 36984 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 50 ms 21248 KB Output is correct
14 Correct 440 ms 51064 KB Output is correct
15 Correct 158 ms 34436 KB Output is correct
16 Correct 332 ms 89724 KB Output is correct
17 Execution timed out 1514 ms 143992 KB Time limit exceeded
18 Halted 0 ms 0 KB -