oj.uz

Submission #187523

# Submission time Handle Problem Language Result Execution time Memory
187523 2020-01-13T02:28:28 Z dndhk Watching (JOI13_watching) C++14
50 / 100
 1000 ms 95500 KB 
#include <bits/stdc++.h>

#define pb push_back

using namespace std;

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

const int MAX_N = 2000;
const ll INFLL = 10000;
int N, P, Q;
vector<ll> v;

ll dp[MAX_N+1][MAX_N+1];
priority_queue<pll, vector<pll>, greater<pll> > pq[MAX_N+1];

int lb(ll x){
	//cout<<"?"<<x<<" ";
	int s = 1, e = v.size()-1, m;
	while(s<e){
		m = (s+e)/2+1;
		//cout<<m<<" "<<v[m]<<endl;

		if(v[m]<=x)	s = m;
		else	e = m-1;
	}
	//cout<<s<<endl;
	return s;
}

bool chk(ll x){
	for(int i=0; i<=N; i++){
		for(int j=0; j<=N; j++)	dp[i][j] = INFLL;
		while(!pq[i].empty())	pq[i].pop();
	}
	dp[0][0] = 0LL;
	//cout<<x<<endl;
	for(int i=0; i<=N; i++){
		for(int j=N; j>=0; j--){
			if(!pq[j].empty()){
				while(!pq[j].empty() && pq[j].top().second<i)	pq[j].pop();
				if(!pq[j].empty()){
					dp[i][j] = pq[j].top().first;
				}	
			}
			//cout<<i<<" "<<j<<" "<<dp[i][j]<<endl;
			if(dp[i][j]==INFLL || i==N)	continue;
			ll k = dp[i][j];
			ll l = v[i+1], r1 = lb(l+x-1LL), r2 = lb(l+2LL*x-1LL);
			//cout<<"*"<<l<<" "<<r1<<" "<<r2<<endl;
			pq[j+1].push({k, r1});
			pq[j].push({k+1, r2});
		}
	}
	for(int i=0; i<=P; i++){
		if(dp[N][i]<=Q)	return true;
	}
	return false;
}

int main(){
	scanf("%d%d%d", &N, &P, &Q);	
	v.pb(0);
	for(int i=1; i<=N; i++){
		ll x; scanf("%lld", &x);
		v.pb(x);
	}
	sort(v.begin(), v.end());
	v.erase(unique(v.begin(), v.end()), v.end());
	N = v.size()-1;
	ll s = 1LL, e = 1000000000LL, m;
	while(s<e){
		m = (s+e)/2LL;
		if(chk(m)){
			e = m;
		}else{
			s = m+1;
		}
	}
	printf("%lld", s);
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:64:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d", &N, &P, &Q); 
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
watching.cpp:67:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   ll x; scanf("%lld", &x);
         ~~~~~^~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 1152 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 476 KB Output is correct
4 Correct 19 ms 1144 KB Output is correct
5 Correct 19 ms 1116 KB Output is correct
6 Correct 18 ms 1144 KB Output is correct
7 Correct 27 ms 1144 KB Output is correct
8 Correct 27 ms 1020 KB Output is correct
9 Correct 28 ms 1124 KB Output is correct
10 Correct 21 ms 1016 KB Output is correct
11 Correct 21 ms 1112 KB Output is correct
12 Correct 20 ms 1144 KB Output is correct
13 Correct 23 ms 1164 KB Output is correct
14 Correct 26 ms 1148 KB Output is correct
15 Correct 27 ms 1156 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1061 ms 95500 KB Time limit exceeded
2 Halted 0 ms 0 KB -