Submission #286885

#	Time	Username	Problem	Language	Result	Execution time	Memory
286885		arnold518	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	8 ms	2688 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 2e5;

int N, K;
char S[MAXN+10];
int P[MAXN+10], Q[MAXN+10];

int main()
{
	scanf("%d%d", &N, &K);
	scanf("%s", S+1);

	vector<int> V;
	P[0]=-1;
	for(int i=1; i<=N; i++)
	{
		if(S[i]=='J') V.push_back(i);
		if(V.size()<K) P[i]=-1;
		else P[i]=V[V.size()-K];
	}
	V.clear();

	Q[N+1]=-1;
	for(int i=N; i>=1; i--)
	{
		if(S[i]=='I') V.push_back(i);
		if(V.size()<K) Q[i]=-1;
		else Q[i]=V[V.size()-K];
	}
	V.clear();

	int ans=2e9;
	for(int i=1; i<=N; i++)
	{
		if(S[i]=='O') V.push_back(i);
		if(V.size()<K) continue;
		else
		{
			int p=V[V.size()-K], q=i;
			int l=P[p-1], r=Q[q+1];
			if(l==-1 || r==-1) continue;
			ans=min(ans, r-l+1);
		}
	}

	if(ans==2e9) return !printf("-1\n");
	printf("%d\n", ans-3*K);
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:24:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   24 |   if(V.size()<K) P[i]=-1;
      |      ~~~~~~~~^~
ho_t2.cpp:33:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   33 |   if(V.size()<K) Q[i]=-1;
      |      ~~~~~~~~^~
ho_t2.cpp:42:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   42 |   if(V.size()<K) continue;
      |      ~~~~~~~~^~
ho_t2.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   16 |  scanf("%d%d", &N, &K);
      |  ~~~~~^~~~~~~~~~~~~~~~
ho_t2.cpp:17:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   17 |  scanf("%s", S+1);
      |  ~~~~~^~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87