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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#103988#6394. Turn on the LightHe_Ren#AC ✓4ms3800kbC++14854b2023-05-08 09:27:342023-05-08 09:27:36

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-05-08 09:27:36]
  • 评测
  • 测评结果：AC
  • 用时：4ms
  • 内存：3800kb
查看
  • [2023-05-08 09:27:34]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int MAXN = 1e6 + 5;

bool vis[MAXN];

int ask(int x)
{
	vis[x] = 1;
	printf("? %d\n",x);
	fflush(stdout);
	int res;
	scanf("%d",&res);
	return res;
}

void answer(int x)
{
	printf("! %d\n",x);
	fflush(stdout);
	exit(0);
}

int main(void)
{
	int n;
	scanf("%d",&n);
	
	int lst = ask(1);
	if(lst == 0) answer(1);
	
	int pos = 1;
	
	int l = 2, r = n;
	while(l < r)
	{
		int mid = (l+r)>>1;
		int cur = ask(mid);
		if(cur == lst) answer(mid);
		
		if(cur > lst) l = mid+1;
		else r = mid-1;
		
		if(l == r) answer(l);
		
		lst = cur;
		if(lst == 0)
		{
			while(vis[pos]) ++pos;
			cur = ask(pos);
			if(cur == lst) answer(pos);
			lst = cur;
			while(vis[l]) ++l;
		}
	}
	
	answer(l);
	return 0;
}
Source code, Language: C++14

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 3776kb

input:

3
1
2

output:

? 1
? 2
! 3

result:

ok Correct position at 3

Test #2:

score: 0
Accepted
time: 2ms
memory: 3560kb

input:

10
1
0
1
0

output:

? 1
? 6
? 2
? 4
! 3

result:

ok Correct position at 3

Test #3:

score: 0
Accepted
time: 1ms
memory: 3532kb

input:

9
1
2
3
3

output:

? 1
? 5
? 7
? 8
! 8

result:

ok Correct position at 8

Test #4:

score: 0
Accepted
time: 2ms
memory: 3596kb

input:

8
1
0
1
1

output:

? 1
? 5
? 2
? 3
! 3

result:

ok Correct position at 3

Test #5:

score: 0
Accepted
time: 2ms
memory: 3564kb

input:

7
1
2
3

output:

? 1
? 4
? 6
! 7

result:

ok Correct position at 7

Test #6:

score: 0
Accepted
time: 2ms
memory: 3564kb

input:

6
1
0
1

output:

? 1
? 4
? 2
! 3

result:

ok Correct position at 3

Test #7:

score: 0
Accepted
time: 2ms
memory: 3608kb

input:

5
1
2
3

output:

? 1
? 3
? 4
! 5

result:

ok Correct position at 5

Test #8:

score: 0
Accepted
time: 2ms
memory: 3560kb

input:

4
1
1

output:

? 1
? 3
! 3

result:

ok Correct position at 3

Test #9:

score: 0
Accepted
time: 0ms
memory: 3500kb

input:

3
1
1

output:

? 1
? 2
! 2

result:

ok Correct position at 2

Test #10:

score: 0
Accepted
time: 2ms
memory: 3592kb

input:

2
1

output:

? 1
! 2

result:

ok Correct position at 2

Test #11:

score: 0
Accepted
time: 0ms
memory: 3532kb

input:

1
0

output:

? 1
! 1

result:

ok Correct position at 1

Test #12:

score: 0
Accepted
time: 2ms
memory: 3796kb

input:

1000000
1
0
1
2
3
2
1
0
1
2
3
4
5
6
7
8
9
10
11
10
9
10

output:

? 1
? 500001
? 2
? 250001
? 375001
? 437501
? 406251
? 390626
? 3
? 382813
? 386719
? 388672
? 389649
? 390137
? 390381
? 390503
? 390564
? 390595
? 390610
? 390618
? 390614
? 390612
! 390613

result:

ok Correct position at 390613

Test #13:

score: 0
Accepted
time: 4ms
memory: 3552kb

input:

999999
1
2
3
2
3
2
1
2
3
4
3
4
5
6
7
8
9
10
11
12

output:

? 1
? 500000
? 750000
? 875000
? 812500
? 843750
? 828125
? 820312
? 824218
? 826171
? 827148
? 826659
? 826903
? 827025
? 827086
? 827117
? 827132
? 827140
? 827144
? 827146
! 827147

result:

ok Correct position at 827147

Test #14:

score: 0
Accepted
time: 4ms
memory: 3784kb

input:

999998
1
0
1
0
1
0
1
0
1
2
3
4
5
6
5
6
7
8
9
8
9
8
9
8

output:

? 1
? 500000
? 2
? 250001
? 3
? 125002
? 4
? 62503
? 5
? 31254
? 46878
? 54690
? 58596
? 60549
? 61526
? 61037
? 61281
? 61403
? 61464
? 61495
? 61479
? 61487
? 61483
? 61485
! 61484

result:

ok Correct position at 61484

Test #15:

score: 0
Accepted
time: 4ms
memory: 3616kb

input:

999997
1
2
3
2
3
2
1
2
3
4
3
4
5
6
7
8
9
10
11
12

output:

? 1
? 499999
? 749998
? 874998
? 812498
? 843748
? 828123
? 820310
? 824216
? 826169
? 827146
? 826657
? 826901
? 827023
? 827084
? 827115
? 827130
? 827138
? 827142
? 827144
! 827145

result:

ok Correct position at 827145

Test #16:

score: 0
Accepted
time: 2ms
memory: 3628kb

input:

999996
1
0
1
2
3
2
1
0
1
2
3
4
5
6
7
8
9
10
11
10
9
10

output:

? 1
? 499999
? 2
? 250000
? 374999
? 437499
? 406249
? 390624
? 3
? 382811
? 386717
? 388670
? 389647
? 390135
? 390379
? 390501
? 390562
? 390593
? 390608
? 390616
? 390612
? 390610
! 390611

result:

ok Correct position at 390611

Test #17:

score: 0
Accepted
time: 4ms
memory: 3620kb

input:

999995
1
2
3
4
5
4
3
4
5
6
5
6
7
8
9
10
11
12
13
14

output:

? 1
? 499998
? 749997
? 874996
? 937496
? 968746
? 953121
? 945308
? 949214
? 951167
? 952144
? 951655
? 951899
? 952021
? 952082
? 952113
? 952128
? 952136
? 952140
? 952142
! 952143

result:

ok Correct position at 952143

Test #18:

score: 0
Accepted
time: 3ms
memory: 3556kb

input:

999994
1
0
1
0
1
2
3
2
1
2
3
4
5
6
7
8
9
10
11
10
9
10

output:

? 1
? 499998
? 2
? 250000
? 3
? 125001
? 187500
? 218750
? 203125
? 195312
? 199218
? 201171
? 202148
? 202636
? 202880
? 203002
? 203063
? 203094
? 203109
? 203117
? 203113
? 203111
! 203112

result:

ok Correct position at 203112

Test #19:

score: 0
Accepted
time: 0ms
memory: 3572kb

input:

999993
1
2
3
4
5
4
3
4
5
6
5
6
7
8
9
10
11
12
13
14

output:

? 1
? 499997
? 749995
? 874994
? 937494
? 968744
? 953119
? 945306
? 949212
? 951165
? 952142
? 951653
? 951897
? 952019
? 952080
? 952111
? 952126
? 952134
? 952138
? 952140
! 952141

result:

ok Correct position at 952141

Test #20:

score: 0
Accepted
time: 4ms
memory: 3544kb

input:

999992
1
0
1
2
3
4
3
2
3
4
5
4
5
6
7
8
9
10
11
10
11

output:

? 1
? 499997
? 2
? 249999
? 374998
? 437497
? 468747
? 453122
? 445309
? 449215
? 451168
? 452145
? 451656
? 451900
? 452022
? 452083
? 452114
? 452129
? 452137
? 452141
? 452139
! 452140

result:

ok Correct position at 452140

Test #21:

score: 0
Accepted
time: 4ms
memory: 3624kb

input:

999991
1
2
3
2
3
2
1
2
3
4
3
4
5
6
7
8
9
10
11
12

output:

? 1
? 499996
? 749994
? 874993
? 812493
? 843743
? 828118
? 820305
? 824211
? 826164
? 827141
? 826652
? 826896
? 827018
? 827079
? 827110
? 827125
? 827133
? 827137
? 827139
! 827140

result:

ok Correct position at 827140

Test #22:

score: 0
Accepted
time: 0ms
memory: 3800kb

input:

1000000
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
3
4
5

output:

? 1
? 500001
? 2
? 250001
? 3
? 125002
? 4
? 62503
? 5
? 31254
? 6
? 15630
? 7
? 7818
? 8
? 3913
? 9
? 1961
? 10
? 985
? 11
? 498
? 12
? 255
? 13
? 134
? 14
? 74
? 15
? 44
? 16
? 30
? 37
? 40
? 42
! 43

result:

ok Correct position at 43

Test #23:

score: 0
Accepted
time: 4ms
memory: 3592kb

input:

999999
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
1

output:

? 1
? 500000
? 2
? 250001
? 3
? 125002
? 4
? 62503
? 5
? 31254
? 6
? 15630
? 7
? 7818
? 8
? 3913
? 9
? 1961
? 10
? 985
? 11
? 498
? 12
? 255
? 13
? 134
? 14
? 74
? 15
? 44
? 59
? 51
! 51

result:

ok Correct position at 51

Test #24:

score: 0
Accepted
time: 1ms
memory: 3612kb

input:

999998
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
1

output:

? 1
? 500000
? 2
? 250001
? 3
? 125002
? 4
? 62503
? 5
? 31254
? 6
? 15630
? 7
? 7818
? 8
? 3913
? 9
? 1961
? 10
? 985
? 11
? 498
? 12
? 255
? 13
? 134
? 14
? 74
? 15
? 44
? 59
? 51
! 51

result:

ok Correct position at 51

Test #25:

score: 0
Accepted
time: 3ms
memory: 3632kb

input:

999997
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
1

output:

? 1
? 499999
? 2
? 250000
? 3
? 125001
? 4
? 62502
? 5
? 31253
? 6
? 15629
? 7
? 7818
? 8
? 3913
? 9
? 1961
? 10
? 985
? 11
? 498
? 12
? 255
? 13
? 134
? 14
? 74
? 15
? 44
? 59
? 51
! 51

result:

ok Correct position at 51

Test #26:

score: 0
Accepted
time: 2ms
memory: 3644kb

input:

1000000
1
2
3
4
5
6
7
8
9
10
11
12
13
12
11
10
11
12
11
12

output:

? 1
? 500001
? 750001
? 875001
? 937501
? 968751
? 984376
? 992188
? 996094
? 998047
? 999024
? 999512
? 999756
? 999878
? 999817
? 999786
? 999771
? 999778
? 999782
? 999780
! 999781

result:

ok Correct position at 999781

Test #27:

score: 0
Accepted
time: 1ms
memory: 3572kb

input:

999999
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
15
16
16

output:

? 1
? 500000
? 750000
? 875000
? 937500
? 968750
? 984375
? 992187
? 996093
? 998046
? 999023
? 999511
? 999755
? 999877
? 999938
? 999969
? 999984
? 999976
? 999980
! 999980

result:

ok Correct position at 999980

Test #28:

score: 0
Accepted
time: 2ms
memory: 3712kb

input:

999998
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
15
16
16

output:

? 1
? 500000
? 749999
? 874999
? 937499
? 968749
? 984374
? 992186
? 996092
? 998045
? 999022
? 999510
? 999754
? 999876
? 999937
? 999968
? 999983
? 999975
? 999979
! 999979

result:

ok Correct position at 999979

Test #29:

score: 0
Accepted
time: 2ms
memory: 3596kb

input:

999997
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
15
16
16

output:

? 1
? 499999
? 749998
? 874998
? 937498
? 968748
? 984373
? 992185
? 996091
? 998044
? 999021
? 999509
? 999753
? 999875
? 999936
? 999967
? 999982
? 999974
? 999978
! 999978

result:

ok Correct position at 999978

Test #30:

score: 0
Accepted
time: 0ms
memory: 3568kb

input:

1000000
1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
13
12
13
12
11

output:

? 1
? 500001
? 2
? 250001
? 375001
? 437501
? 468751
? 484376
? 492188
? 496094
? 498047
? 499024
? 499512
? 499756
? 499878
? 499939
? 499970
? 499954
? 499946
? 499950
? 499948
! 499947

result:

ok Correct position at 499947

Test #31:

score: 0
Accepted
time: 3ms
memory: 3744kb

input:

999999
1
2
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
0
1
2
1
1

output:

? 1
? 500000
? 750000
? 625000
? 2
? 562500
? 3
? 531250
? 4
? 515625
? 5
? 507812
? 6
? 503906
? 7
? 501953
? 8
? 500976
? 9
? 500488
? 10
? 500244
? 11
? 500122
? 12
? 500061
? 500091
? 500076
? 13
? 500068
? 500072
? 500070
! 500070

result:

ok Correct position at 500070

Test #32:

score: 0
Accepted
time: 3ms
memory: 3636kb

input:

999998
1
2
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
1

output:

? 1
? 500000
? 749999
? 624999
? 2
? 562499
? 3
? 531249
? 4
? 515624
? 5
? 507812
? 6
? 503906
? 7
? 501953
? 8
? 500976
? 9
? 500488
? 10
? 500244
? 11
? 500122
? 12
? 500061
? 500091
? 500076
! 500076

result:

ok Correct position at 500076

Test #33:

score: 0
Accepted
time: 0ms
memory: 3616kb

input:

999997
1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
13
14
15
16
15

output:

? 1
? 499999
? 2
? 250000
? 374999
? 437499
? 468749
? 484374
? 492186
? 496092
? 498045
? 499022
? 499510
? 499754
? 499876
? 499937
? 499968
? 499952
? 499960
? 499964
? 499966
! 499965

result:

ok Correct position at 499965

Test #34:

score: 0
Accepted
time: 0ms
memory: 3596kb

input:

1000000
1
0
1
2
1
0
1
0
1
0
1
2
3
4
3
4
5
6
7
6
7
6
5
4

output:

? 1
? 500001
? 2
? 250001
? 375001
? 312501
? 3
? 281251
? 4
? 265626
? 5
? 257813
? 261719
? 263672
? 264649
? 264160
? 264404
? 264526
? 264587
? 264618
? 264602
? 264610
? 264606
? 264604
! 264603

result:

ok Correct position at 264603

Test #35:

score: 0
Accepted
time: 2ms
memory: 3616kb

input:

999999
1
2
1
0
1
0
1
0
1
0
1
2
3
4
3
4
5
6
7
6
7
6
5
4

output:

? 1
? 500000
? 750000
? 625000
? 2
? 562500
? 3
? 531250
? 4
? 515625
? 5
? 507812
? 511718
? 513671
? 514648
? 514159
? 514403
? 514525
? 514586
? 514617
? 514601
? 514609
? 514605
? 514603
! 514602

result:

ok Correct position at 514602

Test #36:

score: 0
Accepted
time: 4ms
memory: 3784kb

input:

999998
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
0
1
2
3
4
5
6
5
6
5
4
3

output:

? 1
? 500000
? 2
? 250001
? 3
? 125002
? 4
? 62503
? 5
? 31254
? 6
? 15630
? 7
? 7818
? 11724
? 9771
? 8
? 8794
? 9282
? 9526
? 9648
? 9709
? 9740
? 9724
? 9732
? 9728
? 9726
! 9725

result:

ok Correct position at 9725

Test #37:

score: 0
Accepted
time: 0ms
memory: 3596kb

input:

999997
1
2
3
2
1
0
1
0
1
2
3
4
3
4
5
6
7
6
7
6
5
4

output:

? 1
? 499999
? 749998
? 874998
? 812498
? 781248
? 2
? 765623
? 3
? 757810
? 761716
? 763669
? 764646
? 764157
? 764401
? 764523
? 764584
? 764615
? 764599
? 764607
? 764603
? 764601
! 764600

result:

ok Correct position at 764600

Test #38:

score: 0
Accepted
time: 1ms
memory: 3636kb

input:

1000000
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

output:

? 1
? 500001
? 750001
? 875001
? 937501
? 968751
? 984376
? 992188
? 996094
? 998047
? 999024
? 999512
? 999756
? 999878
? 999939
? 999970
? 999985
? 999993
? 999997
? 999999
! 1000000

result:

ok Correct position at 1000000

Test #39:

score: 0
Accepted
time: 3ms
memory: 3580kb

input:

999999
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

output:

? 1
? 500000
? 750000
? 875000
? 937500
? 968750
? 984375
? 992187
? 996093
? 998046
? 999023
? 999511
? 999755
? 999877
? 999938
? 999969
? 999984
? 999992
? 999996
? 999998
! 999999

result:

ok Correct position at 999999

Test #40:

score: 0
Accepted
time: 2ms
memory: 3792kb

input:

999998
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

output:

? 1
? 500000
? 749999
? 874999
? 937499
? 968749
? 984374
? 992186
? 996092
? 998045
? 999022
? 999510
? 999754
? 999876
? 999937
? 999968
? 999983
? 999991
? 999995
? 999997
! 999998

result:

ok Correct position at 999998

Test #41:

score: 0
Accepted
time: 1ms
memory: 3540kb

input:

999997
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

output:

? 1
? 499999
? 749998
? 874998
? 937498
? 968748
? 984373
? 992185
? 996091
? 998044
? 999021
? 999509
? 999753
? 999875
? 999936
? 999967
? 999982
? 999990
? 999994
? 999996
! 999997

result:

ok Correct position at 999997

Test #42:

score: 0
Accepted
time: 3ms
memory: 3756kb

input:

1000000
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

output:

? 1
? 500001
? 750001
? 875001
? 937501
? 968751
? 984376
? 992188
? 996094
? 998047
? 999024
? 999512
? 999756
? 999878
? 999939
? 999970
? 999985
? 999993
? 999997
? 999999
! 1000000

result:

ok Correct position at 1000000

Test #43:

score: 0
Accepted
time: 2ms
memory: 3600kb

input:

1000000
0

output:

? 1
! 1

result:

ok Correct position at 1
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Server Time: 2024-12-03 17:33:05 | OpenSource Project