oj.uz

Submission #187534

# Submission time Handle Problem Language Result Execution time Memory
187534 2020-01-13T02:47:33 Z dndhk Watching (JOI13_watching) C++14
50 / 100
 1000 ms 16348 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 = 2002;
const ll INFLL = 10000;
int N, P, Q;
vector<ll> v;

int dp[MAX_N+1][MAX_N+1];

list<pii> dq[2][MAX_N+1];

void add(int idx, int x, int y, int z){
	while(!dq[idx][x].empty() && dq[idx][x].back().first>=z){
		dq[idx][x].pop_back();
	}
	dq[idx][x].push_back({z, y});
}

bool chk(ll x){
	for(int i=0; i<=N; i++){
		for(int j=0; j<=N; j++)	dp[i][j] = INFLL;
		while(!dq[0][i].empty())	dq[0][i].pop_back();
		while(!dq[1][i].empty())	dq[1][i].pop_back();
	}
	dp[0][0] = 0LL;
	//cout<<x<<endl;
	int r1=0, r2=0;
	for(int i=0; i<=N; i++){
		while(r1<v.size()-1 && v[r1+1]<=v[i+1]+x-1LL){
			r1++;
		}
		while(r2<v.size()-1 && v[r2+1]<=v[i+1]+2LL*x-1LL){
			r2++;
		}
		for(int j=N; j>=0; j--){
			while(!dq[0][j].empty() && dq[0][j].front().second<i)	dq[0][j].pop_front();
			while(!dq[1][j].empty() && dq[1][j].front().second<i)	dq[1][j].pop_front();
			if(dq[0][j].empty()){
				if(!dq[1][j].empty())	dp[i][j] = dq[1][j].front().first;
			}else{
				if(dq[1][j].empty())	dp[i][j] = dq[0][j].front().first;
				else{
					dp[i][j] = min(dq[0][j].front().first, dq[1][j].front().first);
				}
			}
			if(dp[i][j]==INFLL || i==N)	continue;
			int k = dp[i][j];
			add(0, j+1, r1, k);
			add(1, j, r2, k+1);
		}
	}
	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());
	sort(v.begin(), 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 'bool chk(ll)':
watching.cpp:37:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(r1<v.size()-1 && v[r1+1]<=v[i+1]+x-1LL){
         ~~^~~~~~~~~~~
watching.cpp:40:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(r2<v.size()-1 && v[r2+1]<=v[i+1]+2LL*x-1LL){
         ~~^~~~~~~~~~~
watching.cpp: In function 'int main()':
watching.cpp:67:7: 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:70:14: 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 17 ms 888 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 11 ms 504 KB Output is correct
4 Correct 16 ms 888 KB Output is correct
5 Correct 16 ms 916 KB Output is correct
6 Correct 16 ms 888 KB Output is correct
7 Correct 15 ms 888 KB Output is correct
8 Correct 16 ms 888 KB Output is correct
9 Correct 17 ms 1060 KB Output is correct
10 Correct 16 ms 888 KB Output is correct
11 Correct 16 ms 860 KB Output is correct
12 Correct 16 ms 1016 KB Output is correct
13 Correct 15 ms 888 KB Output is correct
14 Correct 15 ms 888 KB Output is correct
15 Correct 15 ms 1016 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1031 ms 16348 KB Time limit exceeded
2 Halted 0 ms 0 KB -