oj.uz

Submission #200581

# Submission time Handle Problem Language Result Execution time Memory
200581 2020-02-07T12:56:52 Z quocnguyen1012 Watching (JOI13_watching) C++14
100 / 100
 234 ms 16228 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;
 
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});
}
 
int dp[MAX_N+1][MAX_N+1];
 
bool chk(ll x){
	for(int i=0; i<=N; i++){
		for(int j=0; j<=min(N, P); j++){
			dp[i][j] = INFLL;
		}
	}
	//cout<<x<<endl;
	int r1=0, r2=0;
	dp[0][0] = 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=min(i, P); j>=0; j--){
			if(dp[i][j]==INFLL)	continue;
			if(i==N){
				if(j<=P && dp[i][j]<=Q)	return true;
			}else{
				if(dp[i][j]>Q)	continue;
				dp[r1][j+1] = min(dp[r1][j+1], dp[i][j]);
				dp[r2][j] = min(dp[r2][j], dp[i][j]+1);
			}
		}
	}
	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:58:7: 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:61:14: 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 5 ms 760 KB Output is correct
2 Correct 5 ms 376 KB Output is correct
3 Correct 5 ms 504 KB Output is correct
4 Correct 6 ms 888 KB Output is correct
5 Correct 5 ms 760 KB Output is correct
6 Correct 6 ms 888 KB Output is correct
7 Correct 5 ms 760 KB Output is correct
8 Correct 5 ms 760 KB Output is correct
9 Correct 5 ms 760 KB Output is correct
10 Correct 5 ms 888 KB Output is correct
11 Correct 5 ms 888 KB Output is correct
12 Correct 5 ms 888 KB Output is correct
13 Correct 5 ms 760 KB Output is correct
14 Correct 5 ms 760 KB Output is correct
15 Correct 5 ms 888 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 8444 KB Output is correct
2 Correct 5 ms 504 KB Output is correct
3 Correct 214 ms 15992 KB Output is correct
4 Correct 167 ms 15992 KB Output is correct
5 Correct 29 ms 9080 KB Output is correct
6 Correct 234 ms 16120 KB Output is correct
7 Correct 13 ms 8568 KB Output is correct
8 Correct 34 ms 9336 KB Output is correct
9 Correct 102 ms 14200 KB Output is correct
10 Correct 155 ms 16228 KB Output is correct
11 Correct 32 ms 9208 KB Output is correct
12 Correct 158 ms 16120 KB Output is correct
13 Correct 16 ms 8568 KB Output is correct
14 Correct 16 ms 8568 KB Output is correct
15 Correct 14 ms 8696 KB Output is correct