Submission #421587

#	Time	Username	Problem	Language	Result	Execution time	Memory
421587		Nicholas_Patrick	Sequence (BOI14_sequence)	C++17	100 / 100	575 ms	884 KiB

sequence

#pragma GCC optimize("O3")
#include <cstdio>
#include <queue>
#include <random>
using namespace std;

int singleLookup[1024];
int single(int mask){
	long long ret=0, mult=1;
	if(mask==1)
		return 10;
	for(int i=10; --i;){
		if(mask>>i&1){
			ret+=mult*i;
			mult*=10;
		}
	}
	if(mask&1){
		mult/=10;
		ret+=ret/mult*mult*9;
	}
	return ret;
}
long long solve(vector<int>& masks, int depth=0, bool positive=true){
	if(depth>=15)
		return 1;
	if(masks.size()==0)
		return positive;
	if(masks.size()==1){
		int ret=singleLookup[masks[0]];
		return ret?ret:positive;
	}
	long long ret=102345678888889;
	for(int fu=0; fu<10; fu++){
		vector<int> newMasks((masks.size()-1+fu)/10+1, 0);
		bool reduced=false;
		for(int i=0; i<10; i++){
			int u=fu+i;
			bool additional=u>=10;
			if(additional)
				u-=10;
			for(int j=0; j*10+i<masks.size(); j++){
				int x=masks[j*10+i]&~(1<<u);
				if(x!=masks[j*10+i] and i==0)
					reduced=true;
				newMasks[j+additional]|=x;
			}
		}
		while(not newMasks.empty() and newMasks.back()==0)
			newMasks.pop_back();
		ret=min(ret, solve(newMasks, depth+1, fu==0 and reduced)*10+fu);
	}
	return ret?ret:positive;
}
int main(){
	for(int i=0; i<1024; i++)
		singleLookup[i]=single(i);
	int k;
	scanf("%d", &k);
	vector<int> b(k);
	for(int& i : b)
		scanf("%d", &i), i=1<<i;
	printf("%lld\n", solve(b));
}

Compilation message (stderr)

sequence.cpp: In function 'long long int solve(std::vector<int>&, int, bool)':
sequence.cpp:42:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |    for(int j=0; j*10+i<masks.size(); j++){
      |                 ~~~~~~^~~~~~~~~~~~~
sequence.cpp: In function 'int main()':
sequence.cpp:59:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |  scanf("%d", &k);
      |  ~~~~~^~~~~~~~~~
sequence.cpp:62:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d", &i), i=1<<i;
      |   ~~~~~^~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 33 / 33
• Subtask 3: 25 / 25
• Subtask 4: 33 / 33