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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#143354#8. 小w、小j和小zXiao_mo1001919ms3512kbC++1.3kb2021-11-18 06:57:362021-11-18 06:57:38

answer

//#pragma GCC optimize("Ofast","inline","-ffast-math")
//#pragma GCC target("avx,sse2,sse3,sse4,mmx")
//#pragma GCC optimize(2)
#include<bits/stdc++.h>
#define ll long long
#define inf 1e8
#define rg register
using namespace std;
const int N=1e5+10;
inline ll read(){
	register ll s=0,f=0;
	register char ch=getchar();
	while(!isdigit(ch)) f|=(ch=='-'),ch=getchar();
	while(isdigit(ch)) s=(s<<1)+(s<<3)+(ch^48),ch=getchar();
	return f?-s:s;
}
inline void write(ll x){
    if(x<0) putchar('-'),x=-x;
    if(x>9) write(x/10);
    putchar(x%10+'0');
}
int n,k;
struct data{
	int p,v;
	double x;
}a[N];
double b[N];
inline bool cmp(data a,data b){
	return a.p<b.p;
}
inline bool check(double x){
	for(int i=1;i<=n;i++)a[i].x=a[i].p+x*a[i].v;
	int cnt=0;
	for(int i=1;i<=n;i++){
		if(!cnt||b[cnt]<a[i].x)b[++cnt]=a[i].x;
		if(cnt&&fabs(b[cnt]-a[i].x)<0.00001)continue;
		int t=upper_bound(b+1,b+1+cnt,a[i].x)-b;
		b[t]=a[i].x;
	}
	if(n-cnt<=k)return 1;
	return 0;
}
int main() {
//	freopen("in.txt","r",stdin);
//	freopen("out.txt","w",stdout);
	n=read(),k=read();
	for(int i=1;i<=n;i++)a[i].p=read(),a[i].v=read();
	sort(a+1,a+1+n,cmp);
	double l=0,r=2e9,ans;
	while(r-l>=0.00001){
		double mid=(l+r)/2;
		if(check(mid))ans=l=mid;
		else r=mid;
	}
	if(ans>=2e9-0.0001)printf("Forever");
	else printf("%.4lf",l);
	return 0;
}

Details

小提示:点击横条可展开更详细的信息

Subtask #1:

score: 10
Accepted

Test #1:

score: 10
Accepted
time: 0ms
memory: 1212kb

input:

20 10
-715624307 -28629151
957936621 17210368
-753657459 59049
-40974960 5153632
-402454312 -3450252...

output:

11.3999

result:

ok answer is 11.3999000000

Test #2:

score: 0
Accepted
time: 0ms
memory: 1216kb

input:

20 7
-715624307 -310
957936621 3
-753657459 1
-40974960 5
-402454312 -7424
874144191 -4
-227392025 7...

output:

5850568.5000

result:

ok answer is 5850568.5000000000

Test #3:

score: 0
Accepted
time: 0ms
memory: 1212kb

input:

20 4
-715624307 -1
957936621 3
-753657459 6
-40974960 1
-402454312 -1
874144191 -2
-227392025 9
-808...

output:

3926260.0000

result:

ok answer is 3926260.0000000000

Test #4:

score: 0
Accepted
time: 0ms
memory: 1212kb

input:

20 6
-715624307 -1
957936621 3
-753657459 1
-40974960 1
-402454312 -119
874144191 -1
-227392025 359
...

output:

9635550.8333

result:

ok answer is 9635550.8333000001

Test #5:

score: 0
Accepted
time: 0ms
memory: 1156kb

input:

20 10
-715624307 740210959
-955556582 -615695756
-24759231 771301784
-80855559 560021841
-892686343 ...

output:

Forever

result:

ok OK, forever!

Subtask #2:

score: 20
Accepted

Test #6:

score: 20
Accepted
time: 0ms
memory: 1212kb

input:

200 10
-487405787 3200000
725249085 28629151
-671026855 -4084101
38046635 45435424
-188495128 643634...

output:

0.0039

result:

ok answer is 0.0039000000

Test #7:

score: 0
Accepted
time: 0ms
memory: 1216kb

input:

200 10
-487405787 1
725249085 65536
-671026855 -100000000
38046635 1679616
-188495128 6561
-73172885...

output:

0.0042

result:

ok answer is 0.0041000000

Test #8:

score: 0
Accepted
time: 0ms
memory: 1216kb

input:

200 10
-487405787 3
725249085 2
-671026855 -6
38046635 5
-188495128 14
-731728859 12
-331220744 2
31...

output:

14398.5189

result:

ok answer is 14398.5188000000

Test #9:

score: 0
Accepted
time: 0ms
memory: 1220kb

input:

200 10
-487405787 56
725249085 2
-671026855 -8
38046635 1
-188495128 252
-731728859 28
-331220744 2
...

output:

8320.3684

result:

ok answer is 8320.3684000000

Test #10:

score: 0
Accepted
time: 0ms
memory: 1216kb

input:

200 10
-487405787 11
725249085 8
-671026855 -1
38046635 1
-188495128 125
-731728859 106
-331220744 4...

output:

543.5187

result:

ok answer is 543.5186000000

Test #11:

score: 0
Accepted
time: 0ms
memory: 1160kb

input:

200 10
-584283703 -467650291
-389608337 -287739809
-372147316 -257836606
175915600 328991856
7355243...

output:

Forever

result:

ok OK, forever!

Subtask #3:

score: 15
Accepted

Test #12:

score: 15
Accepted
time: 0ms
memory: 1216kb

input:

200 50
-487405787 3200000
725249085 28629151
-671026855 -4084101
38046635 45435424
-188495128 643634...

output:

0.0359

result:

ok answer is 0.0359000000

Test #13:

score: 0
Accepted
time: 0ms
memory: 1216kb

input:

200 100
-487405787 690807104
725249085 2685619
-671026855 -18399744
38046635 862801408
-188495128 54...

output:

0.1288

result:

ok answer is 0.1288000000

Test #14:

score: 0
Accepted
time: 0ms
memory: 1220kb

input:

200 90
-487405787 3
725249085 2
-671026855 -6
38046635 5
-188495128 14
-731728859 12
-331220744 2
31...

output:

3184277.2308

result:

ok answer is 3184277.2307000002

Test #15:

score: 0
Accepted
time: 0ms
memory: 1220kb

input:

200 60
-487405787 56
725249085 2
-671026855 -8
38046635 1
-188495128 252
-731728859 28
-331220744 2
...

output:

572916.7619

result:

ok answer is 572916.7619000000

Test #16:

score: 0
Accepted
time: 1ms
memory: 1216kb

input:

200 30
-487405787 11
725249085 8
-671026855 -1
38046635 1
-188495128 125
-731728859 106
-331220744 4...

output:

7362.4506

result:

ok answer is 7362.4506000000

Test #17:

score: 0
Accepted
time: 0ms
memory: 1160kb

input:

200 75
-584283703 -510093529
-389608337 -734253121
-372147316 -257836606
175915600 -355171217
735524...

output:

Forever

result:

ok OK, forever!

Subtask #4:

score: 15
Accepted

Test #18:

score: 15
Accepted
time: 3ms
memory: 1256kb

input:

2000 10
882856800 -387420489
866607093 -134217728
481381898 1
-488180557 1953125
-783185249 -19683
-...

output:

0.0002

result:

ok answer is 0.0001000000

Test #19:

score: 0
Accepted
time: 4ms
memory: 1256kb

input:

2000 10
882856800 -177147
866607093 -48828125
481381898 1
-488180557 48828125
-783185249 -362797056
...

output:

0.0001

result:

ok answer is 0.0001000000

Test #20:

score: 0
Accepted
time: 0ms
memory: 1252kb

input:

2000 10
882856800 -1
866607093 -396
481381898 21
-488180557 6
-783185249 -10
-816111307 -33761
99248...

output:

2.6237

result:

ok answer is 2.6237000000

Test #21:

score: 0
Accepted
time: 2ms
memory: 1252kb

input:

2000 10
882856800 -3
866607093 -2
481381898 12
-488180557 8639109
-783185249 -12
-816111307 -96
9924...

output:

0.0008

result:

ok answer is 0.0008000000

Test #22:

score: 0
Accepted
time: 3ms
memory: 1256kb

input:

2000 10
882856800 -1
866607093 -10
481381898 406927
-488180557 1
-783185249 -1483
-816111307 -8
9924...

output:

0.0003

result:

ok answer is 0.0003000000

Test #23:

score: 0
Accepted
time: 1ms
memory: 1200kb

input:

2000 10
784172079 808971860
81381899 71917076
-712636352 -738530531
-622770179 -640667385
119667134 ...

output:

Forever

result:

ok OK, forever!

Subtask #5:

score: 20
Accepted

Test #24:

score: 20
Accepted
time: 3ms
memory: 1256kb

input:

2000 200
882856800 -177147
866607093 -48828125
481381898 1
-488180557 48828125
-783185249 -362797056...

output:

0.0024

result:

ok answer is 0.0024000000

Test #25:

score: 0
Accepted
time: 4ms
memory: 1252kb

input:

2000 500
882856800 -46656
866607093 -1000000
481381898 64000000
-488180557 481890304
-783185249 -466...

output:

0.0056

result:

ok answer is 0.0056000000

Test #26:

score: 0
Accepted
time: 2ms
memory: 1244kb

input:

2000 1200
882856800 -2000376
866607093 -344472101
481381898 97336
-488180557 278445077
-783185249 -1...

output:

0.0330

result:

ok answer is 0.0330000000

Test #27:

score: 0
Accepted
time: 3ms
memory: 1256kb

input:

2000 900
882856800 -1
866607093 -40
481381898 2
-488180557 2
-783185249 -1
-816111307 -70227
9924839...

output:

313683.6667

result:

ok answer is 313683.6667000000

Test #28:

score: 0
Accepted
time: 0ms
memory: 1256kb

input:

2000 600
882856800 -1
866607093 -396
481381898 21
-488180557 6
-783185249 -10
-816111307 -33761
9924...

output:

45162.5556

result:

ok answer is 45162.5555000000

Test #29:

score: 0
Accepted
time: 0ms
memory: 1256kb

input:

2000 400
882856800 -8
866607093 -99
481381898 1
-488180557 55
-783185249 -2
-816111307 -174
99248396...

output:

2145.9655

result:

ok answer is 2145.9655000000

Test #30:

score: 0
Accepted
time: 0ms
memory: 1248kb

input:

2000 200
882856800 -1
866607093 -10
481381898 406927
-488180557 1
-783185249 -1483
-816111307 -8
992...

output:

3.4149

result:

ok answer is 3.4149000000

Test #31:

score: 0
Accepted
time: 0ms
memory: 1196kb

input:

2000 975
784172079 808971860
81381899 71917076
-712636352 -738530531
-622770179 -58502471
119667134 ...

output:

Forever

result:

ok OK, forever!

Subtask #6:

score: 20
Accepted

Test #32:

score: 20
Accepted
time: 263ms
memory: 3052kb

input:

99991 66666
-678240367 702595369
-125056128 663054848
574742591 -405224
-82244469 -11697083
55763190...

output:

0.0013

result:

ok answer is 0.0013000000

Test #33:

score: 0
Accepted
time: 218ms
memory: 3192kb

input:

99992 45678
-505891895 4096
409303335 -387420489
800445369 -387420489
324934094 531441
-800995856 75...

output:

0.0009

result:

ok answer is 0.0009000000

Test #34:

score: 0
Accepted
time: 219ms
memory: 3328kb

input:

99993 32768
972961680 -512
-622461107 -512
-65245375 387420489
-652933487 40353607
919122483 -134217...

output:

0.0009

result:

ok answer is 0.0009000000

Test #35:

score: 0
Accepted
time: 196ms
memory: 3416kb

input:

99994 20102
-740844274 -2048
489732031 177147
964768051 1
-652641626 -48828125
-21363456 -48828125
8...

output:

0.0002

result:

ok answer is 0.0002000000

Test #36:

score: 0
Accepted
time: 178ms
memory: 3248kb

input:

99995 45454
-410995107 39
894702367 13
-426401694 -77
800430197 -1
-295413329 -9
708661134 -4
415710...

output:

6448.5000

result:

ok answer is 6448.5000000000

Test #37:

score: 0
Accepted
time: 159ms
memory: 3316kb

input:

99996 35555
-14445778 13
-451475811 -3
444048318 -13004
422621424 -1
742439995 -2
723182696 -7
68727...

output:

1573.3333

result:

ok answer is 1573.3333000000

Test #38:

score: 0
Accepted
time: 165ms
memory: 3384kb

input:

99997 25600
-730866353 10
-218920426 -2
64717974 -1
137126596 -5
46821900 10155
745056512 17285
-964...

output:

119.0812

result:

ok answer is 119.0812000000

Test #39:

score: 0
Accepted
time: 147ms
memory: 3440kb

input:

99998 15263
-467407842 -1
-422165068 -2
915790698 -332
354357273 2
387305689 1714
-445403298 704
-83...

output:

1.4888

result:

ok answer is 1.4888000000

Test #40:

score: 0
Accepted
time: 140ms
memory: 3512kb

input:

99999 4999
-845589366 -183
771287727 -36
409548298 7543
-261071768 52
-182275548 3385
-137396908 121...

output:

0.0010

result:

ok answer is 0.0010000000

Test #41:

score: 0
Accepted
time: 208ms
memory: 3200kb

input:

100000 48364
979472386 980717496
207916820 208951865
-236221008 -237374910
348596303 348678721
70817...

output:

Forever

result:

ok OK, forever!

Extra Test:

score: 0
Extra Test Passed