Submission #375427

#	Time	Username	Problem	Language	Result	Execution time	Memory
375427		astoria	Painting Walls (APIO20_paint)	C++14	100 / 100	1157 ms	17900 KiB

paint

#include "bits/stdc++.h"
#include "paint.h"
using namespace std;
 
int minimumInstructions(int N, int M, int K, std::vector<int> C, std::vector<int> A, std::vector<std::vector<int>> B){
	vector<int> f[K+5]; //for the colour i, who can do?
	for(int i=0; i<M; i++){
		for(int j=0; j<A[i]; j++){
			int col = B[i][j];
			f[col].push_back(i);
		}
	}
	
	int best[N+5]; memset(best,0,sizeof(best));
	int lst[M+5],nxt[M+5]; memset(lst,0,sizeof(lst)); memset(nxt,0,sizeof(nxt));
	vector<int> lst_pos,nxt_pos;
	for(int j : f[C[0]]){
		lst[j] = 1;
		best[0]=max(best[0],lst[j]);
		lst_pos.push_back(j);
	}
	
	for(int i=1; i<N; i++){
		
		for(int j : nxt_pos) nxt[j]=0;
		while(!nxt_pos.empty()) nxt_pos.pop_back();
		
		for(int j : f[C[i]]){
			nxt[j] = 1;
			int las = j-1; if(las<0) las+=M;
			nxt[j] += lst[las];
			best[i]=max(best[i],nxt[j]);
			
			nxt_pos.push_back(j);
		}
		
		for(int j : lst_pos) lst[j]=0;
		while(!lst_pos.empty()) lst_pos.pop_back();
		
		for(int j : nxt_pos) lst[j] = nxt[j];
		
		for(int j : nxt_pos) lst_pos.push_back(j);
	}
	
	int dp[N+5];
	multiset<int> mns; mns.insert(0);
	for(int i=0; i<N; i++){
		if(best[i]<M) dp[i]=1e9;
		else dp[i]=(*mns.begin())+1;
		mns.insert(dp[i]);
		if(mns.size()>M&&i>=M) mns.erase(mns.find(dp[i-M]));
		else if(mns.size()>M) mns.erase(0);
	}
	if(dp[N-1]>=1e6) return -1;
	return dp[N-1];
}

Compilation message (stderr)

paint.cpp: In function 'int minimumInstructions(int, int, int, std::vector<int>, std::vector<int>, std::vector<std::vector<int> >)':
paint.cpp:51:16: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   51 |   if(mns.size()>M&&i>=M) mns.erase(mns.find(dp[i-M]));
      |      ~~~~~~~~~~^~
paint.cpp:52:21: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   52 |   else if(mns.size()>M) mns.erase(0);
      |           ~~~~~~~~~~^~

• Subtask 1: 12 / 12
• Subtask 2: 15 / 15
• Subtask 3: 13 / 13
• Subtask 4: 23 / 23
• Subtask 5: 37 / 37