Submission #320557

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
320557	2020-11-09T05:43:57 Z	arnold518	Sparklers (JOI17_sparklers)	C++14	50 / 100	48 ms	1388 KB

sparklers

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

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

const int MAXN = 1000;
const ll INF = 1e18;

int N, K;
ll T, A[MAXN+10], B[MAXN+10];

bool dp[MAXN+10][MAXN+10];

bool decide(ll X)
{
	X*=2;
	if(T*X>(ll)1e9) return true;
	for(int i=1; i<=N; i++) B[i]=A[i]-i*T*X;
	//for(int i=1; i<=N; i++) printf("%lld ", A[i]); printf(" : %lld\n", X);

	for(int r=1; r<=N; r++) for(int l=r; l>=1; l--)
	{
		if(l==r)
		{
			if(l==K) dp[l][r]=1;
			else dp[l][r]=0;
		}
		else
		{
			dp[l][r]=dp[l+1][r]|dp[l][r-1];
			if(B[l]<B[r]) dp[l][r]=0;
		}
	}
	return dp[1][N];

	int l=K, r=K;
	ll lv=B[l], rv=B[r];
	while(!(l==0 && r==N+1))
	{
		int bl=l, br=r;
		lv=-INF;
		for(; l>=1 && B[l]>=rv; l--) lv=max(lv, B[l]);
		rv=INF;
		for(; r<=N && B[r]<=lv; r++) rv=min(rv, B[r]);
		//printf("%d %d\n", l, r);
		if(l==bl && r==br) return false;
		l++; r--;
	}
	//printf("WOW %lld\n", X);
	return true;
}

int main()
{
	scanf("%d%d%lld", &N, &K, &T);
	for(int i=1; i<=N; i++) scanf("%lld", &A[i]);

	ll lo=-1, hi=1e9+10;
	while(lo+1<hi)
	{
		ll mid=lo+hi>>1;
		if(decide(mid)) hi=mid;
		else lo=mid;
	}
	printf("%lld\n", hi);
}

Compilation message

sparklers.cpp: In function 'int main()':
sparklers.cpp:63:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   63 |   ll mid=lo+hi>>1;
      |          ~~^~~
sparklers.cpp:57:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   57 |  scanf("%d%d%lld", &N, &K, &T);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:58:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   58 |  for(int i=1; i<=N; i++) scanf("%lld", &A[i]);
      |                          ~~~~~^~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	364 KB	Output is correct
2	Correct	0 ms	364 KB	Output is correct
3	Correct	0 ms	364 KB	Output is correct
4	Correct	1 ms	360 KB	Output is correct
5	Correct	0 ms	364 KB	Output is correct
6	Correct	0 ms	364 KB	Output is correct
7	Correct	1 ms	364 KB	Output is correct
8	Correct	1 ms	364 KB	Output is correct
9	Correct	1 ms	364 KB	Output is correct
10	Correct	0 ms	364 KB	Output is correct
11	Correct	0 ms	364 KB	Output is correct
12	Correct	0 ms	364 KB	Output is correct
13	Correct	0 ms	364 KB	Output is correct
14	Correct	0 ms	364 KB	Output is correct
15	Correct	1 ms	364 KB	Output is correct
16	Correct	0 ms	364 KB	Output is correct
17	Correct	0 ms	364 KB	Output is correct
18	Correct	0 ms	364 KB	Output is correct
19	Correct	0 ms	364 KB	Output is correct
20	Correct	0 ms	364 KB	Output is correct
21	Correct	1 ms	364 KB	Output is correct

Subtask #2
20.0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	364 KB	Output is correct
2	Correct	0 ms	364 KB	Output is correct
3	Correct	0 ms	364 KB	Output is correct
4	Correct	1 ms	360 KB	Output is correct
5	Correct	0 ms	364 KB	Output is correct
6	Correct	0 ms	364 KB	Output is correct
7	Correct	1 ms	364 KB	Output is correct
8	Correct	1 ms	364 KB	Output is correct
9	Correct	1 ms	364 KB	Output is correct
10	Correct	0 ms	364 KB	Output is correct
11	Correct	0 ms	364 KB	Output is correct
12	Correct	0 ms	364 KB	Output is correct
13	Correct	0 ms	364 KB	Output is correct
14	Correct	0 ms	364 KB	Output is correct
15	Correct	1 ms	364 KB	Output is correct
16	Correct	0 ms	364 KB	Output is correct
17	Correct	0 ms	364 KB	Output is correct
18	Correct	0 ms	364 KB	Output is correct
19	Correct	0 ms	364 KB	Output is correct
20	Correct	0 ms	364 KB	Output is correct
21	Correct	1 ms	364 KB	Output is correct
22	Correct	25 ms	1004 KB	Output is correct
23	Correct	13 ms	876 KB	Output is correct
24	Correct	24 ms	1004 KB	Output is correct
25	Correct	46 ms	1380 KB	Output is correct
26	Correct	43 ms	1380 KB	Output is correct
27	Correct	44 ms	1380 KB	Output is correct
28	Correct	46 ms	1388 KB	Output is correct
29	Correct	46 ms	1380 KB	Output is correct
30	Correct	45 ms	1380 KB	Output is correct
31	Correct	46 ms	1260 KB	Output is correct
32	Correct	48 ms	1380 KB	Output is correct
33	Correct	45 ms	1380 KB	Output is correct
34	Correct	45 ms	1380 KB	Output is correct
35	Correct	44 ms	1380 KB	Output is correct
36	Correct	46 ms	1380 KB	Output is correct
37	Correct	47 ms	1260 KB	Output is correct
38	Correct	46 ms	1260 KB	Output is correct
39	Correct	46 ms	1380 KB	Output is correct
40	Correct	45 ms	1380 KB	Output is correct

Subtask #3
0 / 50.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	364 KB	Output is correct
2	Correct	0 ms	364 KB	Output is correct
3	Correct	0 ms	364 KB	Output is correct
4	Correct	1 ms	360 KB	Output is correct
5	Correct	0 ms	364 KB	Output is correct
6	Correct	0 ms	364 KB	Output is correct
7	Correct	1 ms	364 KB	Output is correct
8	Correct	1 ms	364 KB	Output is correct
9	Correct	1 ms	364 KB	Output is correct
10	Correct	0 ms	364 KB	Output is correct
11	Correct	0 ms	364 KB	Output is correct
12	Correct	0 ms	364 KB	Output is correct
13	Correct	0 ms	364 KB	Output is correct
14	Correct	0 ms	364 KB	Output is correct
15	Correct	1 ms	364 KB	Output is correct
16	Correct	0 ms	364 KB	Output is correct
17	Correct	0 ms	364 KB	Output is correct
18	Correct	0 ms	364 KB	Output is correct
19	Correct	0 ms	364 KB	Output is correct
20	Correct	0 ms	364 KB	Output is correct
21	Correct	1 ms	364 KB	Output is correct
22	Correct	25 ms	1004 KB	Output is correct
23	Correct	13 ms	876 KB	Output is correct
24	Correct	24 ms	1004 KB	Output is correct
25	Correct	46 ms	1380 KB	Output is correct
26	Correct	43 ms	1380 KB	Output is correct
27	Correct	44 ms	1380 KB	Output is correct
28	Correct	46 ms	1388 KB	Output is correct
29	Correct	46 ms	1380 KB	Output is correct
30	Correct	45 ms	1380 KB	Output is correct
31	Correct	46 ms	1260 KB	Output is correct
32	Correct	48 ms	1380 KB	Output is correct
33	Correct	45 ms	1380 KB	Output is correct
34	Correct	45 ms	1380 KB	Output is correct
35	Correct	44 ms	1380 KB	Output is correct
36	Correct	46 ms	1380 KB	Output is correct
37	Correct	47 ms	1260 KB	Output is correct
38	Correct	46 ms	1260 KB	Output is correct
39	Correct	46 ms	1380 KB	Output is correct
40	Correct	45 ms	1380 KB	Output is correct
41	Incorrect	1 ms	364 KB	Output isn't correct
42	Halted	0 ms	0 KB	-

Submission #320557

Compilation message

Subtask #1 30.0 / 30.0

Subtask #2 20.0 / 20.0

Subtask #3 0 / 50.0

Subtask #1
30.0 / 30.0

Subtask #2
20.0 / 20.0

Subtask #3
0 / 50.0