Submission #679520

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
679520	2023-01-08T12:45:35 Z	jamezzz	Event Hopping (BOI22_events)	C++17	100 / 100	153 ms	40256 KB

events

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

#ifdef DEBUG
#define dbg(...) printf(__VA_ARGS__);
#define getchar_unlocked getchar
#else
#define dbg(...)
#endif
#define sf scanf
#define pf printf
#define fi first
#define se second
#define pb push_back
#define psf push_front
#define ppb pop_back
#define ppf pop_front
#define sz(x) (int)x.size()
#define mnto(x,y) x=min(x,(__typeof__(x))y)
#define mxto(x,y) x=max(x,(__typeof__(x))y)
#define INF 1023456789
#define LINF 1023456789123456789
#define all(x) x.begin(),x.end()
#define lb(x,v) (lower_bound(all(x),v)-x.begin())
#define ub(x,v) (upper_bound(all(x),v)-x.begin())
#define disc(x) sort(all(x));x.resize(unique(all(x))-x.begin());
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef pair<ll,ll> pll;
typedef tuple<int,int,int> iii;
typedef tuple<int,int,int,int> iiii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
mt19937 rng(time(0));

#define mod 1000000007

inline int add(int a,int b){
	int r=a+b;
	while(r>=mod)r-=mod;
	while(r<0)r+=mod;
	return r;
}

inline int mult(int a,int b){
	return (int)(((ll)(a*b))%mod);
}

inline int rd(){
	int x=0;
	char ch=getchar_unlocked();
	while(!(ch&16))ch=getchar();//keep reading while current character is whitespace
    while(ch&16){//this will break when ‘\n’ or ‘ ‘ is encountered
		x=(x<<3)+(x<<1)+(ch&15);
		ch=getchar_unlocked();
	}
	return x;
}

#define maxn 100005

int n,q,m,s[maxn],e[maxn],p[20][maxn];
ii st[20][2*maxn];
vector<int> d;

inline ii qmn(int l,int r){
	int k=31-__builtin_clz(r-l+1);
	return min(st[k][l],st[k][r-(1<<k)+1]);
}

int main(){
	sf("%d%d",&n,&q);
	for(int i=0;i<n;++i){
		sf("%d%d",&s[i],&e[i]);
		d.pb(s[i]);d.pb(e[i]);
	}
	disc(d);
	for(int i=0;i<n;++i){
		s[i]=lb(d,s[i]);
		e[i]=lb(d,e[i]);
	}
	m=sz(d);
	for(int i=0;i<m;++i)st[0][i]={INF,-1};
	for(int i=0;i<n;++i)mnto(st[0][e[i]],ii(s[i],i));
	for(int k=1;k<20;++k){
		for(int i=0;i+(1<<k)<=m;++i){
			st[k][i]=min(st[k-1][i],st[k-1][i+(1<<k-1)]);
		}
	}
	
	for(int i=0;i<n;++i)p[0][i]=qmn(s[i],e[i]).se;
	for(int k=0;k<19;++k){
		for(int i=0;i<n;++i){
			if(p[k][i]==-1)p[k+1][i]=-1;
			else p[k+1][i]=p[k][p[k][i]];
		}
	}
	
	for(int i=0;i<q;++i){
		int x,y;sf("%d%d",&x,&y);
		if(x==y){
			pf("0\n");
			continue;
		}
		--x,--y;
		if(e[y]<e[x]){
			pf("impossible\n");
			continue;
		}
		if(s[y]<=e[x]){
			pf("1\n");
			continue;
		}
		int cur=y,ans=0;
		for(int k=19;k>=0;--k){
			int pcur=p[k][cur];
			if(pcur!=-1&&e[x]<s[pcur]){
				cur=pcur;
				ans+=1<<k;
			}
		}
		int pcur=p[0][cur];
		if(pcur==-1||e[x]<s[pcur]){
			pf("impossible\n");
		}
		else pf("%d\n",ans+2);
	}
}

/*
10 10
0 1
1 5
2 4
3 5
5 8
6 8
6 7
7 10
9 11
5 12
*/

Compilation message

events.cpp: In function 'int main()':
events.cpp:89:43: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   89 |    st[k][i]=min(st[k-1][i],st[k-1][i+(1<<k-1)]);
      |                                          ~^~
events.cpp:74:4: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |  sf("%d%d",&n,&q);
      |    ^
events.cpp:76:5: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |   sf("%d%d",&s[i],&e[i]);
      |     ^
events.cpp:102:13: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |   int x,y;sf("%d%d",&x,&y);
      |             ^

Subtask #1

10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	102 ms	22780 KB	Output is correct
3	Correct	113 ms	22764 KB	Output is correct
4	Correct	148 ms	22720 KB	Output is correct
5	Correct	127 ms	27204 KB	Output is correct
6	Correct	126 ms	28484 KB	Output is correct
7	Correct	130 ms	28860 KB	Output is correct
8	Correct	139 ms	40128 KB	Output is correct
9	Correct	139 ms	40124 KB	Output is correct
10	Correct	120 ms	26148 KB	Output is correct
11	Correct	141 ms	31552 KB	Output is correct
12	Correct	66 ms	25532 KB	Output is correct

Subtask #2

10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	1 ms	596 KB	Output is correct
4	Correct	1 ms	596 KB	Output is correct
5	Correct	1 ms	596 KB	Output is correct
6	Correct	1 ms	596 KB	Output is correct
7	Correct	1 ms	712 KB	Output is correct
8	Correct	1 ms	744 KB	Output is correct
9	Correct	1 ms	456 KB	Output is correct

Subtask #3

15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	1 ms	596 KB	Output is correct
4	Correct	1 ms	596 KB	Output is correct
5	Correct	1 ms	596 KB	Output is correct
6	Correct	1 ms	596 KB	Output is correct
7	Correct	1 ms	712 KB	Output is correct
8	Correct	1 ms	744 KB	Output is correct
9	Correct	1 ms	456 KB	Output is correct
10	Correct	1 ms	340 KB	Output is correct
11	Correct	1 ms	340 KB	Output is correct
12	Correct	1 ms	596 KB	Output is correct
13	Correct	1 ms	596 KB	Output is correct
14	Correct	1 ms	580 KB	Output is correct
15	Correct	1 ms	620 KB	Output is correct
16	Correct	1 ms	724 KB	Output is correct
17	Correct	1 ms	724 KB	Output is correct
18	Correct	1 ms	468 KB	Output is correct
19	Correct	36 ms	3076 KB	Output is correct
20	Correct	36 ms	2892 KB	Output is correct
21	Correct	37 ms	3132 KB	Output is correct
22	Correct	32 ms	3296 KB	Output is correct
23	Correct	27 ms	3648 KB	Output is correct
24	Correct	27 ms	3568 KB	Output is correct
25	Correct	42 ms	3232 KB	Output is correct

Subtask #4

15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	1 ms	596 KB	Output is correct
4	Correct	1 ms	596 KB	Output is correct
5	Correct	1 ms	596 KB	Output is correct
6	Correct	1 ms	596 KB	Output is correct
7	Correct	1 ms	712 KB	Output is correct
8	Correct	1 ms	744 KB	Output is correct
9	Correct	1 ms	456 KB	Output is correct
10	Correct	1 ms	340 KB	Output is correct
11	Correct	1 ms	340 KB	Output is correct
12	Correct	1 ms	584 KB	Output is correct
13	Correct	1 ms	596 KB	Output is correct
14	Correct	1 ms	596 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	1 ms	724 KB	Output is correct
17	Correct	2 ms	724 KB	Output is correct
18	Correct	1 ms	468 KB	Output is correct
19	Correct	70 ms	24148 KB	Output is correct
20	Correct	68 ms	23252 KB	Output is correct
21	Correct	71 ms	23948 KB	Output is correct
22	Correct	79 ms	28976 KB	Output is correct
23	Correct	80 ms	37856 KB	Output is correct
24	Correct	84 ms	37948 KB	Output is correct
25	Correct	26 ms	11092 KB	Output is correct

Subtask #5

20.0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	98 ms	22780 KB	Output is correct
2	Correct	114 ms	22724 KB	Output is correct
3	Correct	145 ms	22660 KB	Output is correct
4	Correct	141 ms	40256 KB	Output is correct
5	Correct	123 ms	26168 KB	Output is correct
6	Correct	131 ms	39804 KB	Output is correct
7	Correct	133 ms	39752 KB	Output is correct
8	Correct	120 ms	39912 KB	Output is correct
9	Correct	80 ms	37808 KB	Output is correct
10	Correct	123 ms	39464 KB	Output is correct
11	Correct	115 ms	39236 KB	Output is correct
12	Correct	122 ms	39376 KB	Output is correct

Subtask #6

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	102 ms	22780 KB	Output is correct
3	Correct	113 ms	22764 KB	Output is correct
4	Correct	148 ms	22720 KB	Output is correct
5	Correct	127 ms	27204 KB	Output is correct
6	Correct	126 ms	28484 KB	Output is correct
7	Correct	130 ms	28860 KB	Output is correct
8	Correct	139 ms	40128 KB	Output is correct
9	Correct	139 ms	40124 KB	Output is correct
10	Correct	120 ms	26148 KB	Output is correct
11	Correct	141 ms	31552 KB	Output is correct
12	Correct	66 ms	25532 KB	Output is correct
13	Correct	0 ms	340 KB	Output is correct
14	Correct	0 ms	340 KB	Output is correct
15	Correct	1 ms	596 KB	Output is correct
16	Correct	1 ms	596 KB	Output is correct
17	Correct	1 ms	596 KB	Output is correct
18	Correct	1 ms	596 KB	Output is correct
19	Correct	1 ms	712 KB	Output is correct
20	Correct	1 ms	744 KB	Output is correct
21	Correct	1 ms	456 KB	Output is correct
22	Correct	1 ms	340 KB	Output is correct
23	Correct	1 ms	340 KB	Output is correct
24	Correct	1 ms	596 KB	Output is correct
25	Correct	1 ms	596 KB	Output is correct
26	Correct	1 ms	580 KB	Output is correct
27	Correct	1 ms	620 KB	Output is correct
28	Correct	1 ms	724 KB	Output is correct
29	Correct	1 ms	724 KB	Output is correct
30	Correct	1 ms	468 KB	Output is correct
31	Correct	36 ms	3076 KB	Output is correct
32	Correct	36 ms	2892 KB	Output is correct
33	Correct	37 ms	3132 KB	Output is correct
34	Correct	32 ms	3296 KB	Output is correct
35	Correct	27 ms	3648 KB	Output is correct
36	Correct	27 ms	3568 KB	Output is correct
37	Correct	42 ms	3232 KB	Output is correct
38	Correct	1 ms	340 KB	Output is correct
39	Correct	1 ms	340 KB	Output is correct
40	Correct	1 ms	584 KB	Output is correct
41	Correct	1 ms	596 KB	Output is correct
42	Correct	1 ms	596 KB	Output is correct
43	Correct	2 ms	580 KB	Output is correct
44	Correct	1 ms	724 KB	Output is correct
45	Correct	2 ms	724 KB	Output is correct
46	Correct	1 ms	468 KB	Output is correct
47	Correct	70 ms	24148 KB	Output is correct
48	Correct	68 ms	23252 KB	Output is correct
49	Correct	71 ms	23948 KB	Output is correct
50	Correct	79 ms	28976 KB	Output is correct
51	Correct	80 ms	37856 KB	Output is correct
52	Correct	84 ms	37948 KB	Output is correct
53	Correct	26 ms	11092 KB	Output is correct
54	Correct	98 ms	22780 KB	Output is correct
55	Correct	114 ms	22724 KB	Output is correct
56	Correct	145 ms	22660 KB	Output is correct
57	Correct	141 ms	40256 KB	Output is correct
58	Correct	123 ms	26168 KB	Output is correct
59	Correct	131 ms	39804 KB	Output is correct
60	Correct	133 ms	39752 KB	Output is correct
61	Correct	120 ms	39912 KB	Output is correct
62	Correct	80 ms	37808 KB	Output is correct
63	Correct	123 ms	39464 KB	Output is correct
64	Correct	115 ms	39236 KB	Output is correct
65	Correct	122 ms	39376 KB	Output is correct
66	Correct	0 ms	340 KB	Output is correct
67	Correct	98 ms	25792 KB	Output is correct
68	Correct	116 ms	25792 KB	Output is correct
69	Correct	153 ms	25816 KB	Output is correct
70	Correct	124 ms	27172 KB	Output is correct
71	Correct	123 ms	28480 KB	Output is correct
72	Correct	124 ms	28864 KB	Output is correct
73	Correct	136 ms	40128 KB	Output is correct
74	Correct	147 ms	40172 KB	Output is correct
75	Correct	115 ms	26152 KB	Output is correct
76	Correct	128 ms	31840 KB	Output is correct
77	Correct	67 ms	25532 KB	Output is correct
78	Correct	0 ms	340 KB	Output is correct
79	Correct	1 ms	624 KB	Output is correct
80	Correct	1 ms	584 KB	Output is correct
81	Correct	1 ms	596 KB	Output is correct
82	Correct	1 ms	620 KB	Output is correct
83	Correct	1 ms	724 KB	Output is correct
84	Correct	1 ms	724 KB	Output is correct
85	Correct	1 ms	468 KB	Output is correct
86	Correct	36 ms	3096 KB	Output is correct
87	Correct	40 ms	2916 KB	Output is correct
88	Correct	38 ms	3144 KB	Output is correct
89	Correct	31 ms	3276 KB	Output is correct
90	Correct	26 ms	3616 KB	Output is correct
91	Correct	24 ms	3668 KB	Output is correct
92	Correct	33 ms	3332 KB	Output is correct
93	Correct	68 ms	24116 KB	Output is correct
94	Correct	65 ms	23264 KB	Output is correct
95	Correct	73 ms	23952 KB	Output is correct
96	Correct	74 ms	28988 KB	Output is correct
97	Correct	77 ms	37824 KB	Output is correct
98	Correct	81 ms	37876 KB	Output is correct
99	Correct	25 ms	11064 KB	Output is correct
100	Correct	138 ms	39744 KB	Output is correct
101	Correct	137 ms	39728 KB	Output is correct
102	Correct	118 ms	39848 KB	Output is correct
103	Correct	129 ms	39368 KB	Output is correct
104	Correct	112 ms	39236 KB	Output is correct
105	Correct	120 ms	39360 KB	Output is correct
106	Correct	111 ms	21916 KB	Output is correct
107	Correct	147 ms	25284 KB	Output is correct
108	Correct	113 ms	25936 KB	Output is correct
109	Correct	113 ms	26044 KB	Output is correct
110	Correct	108 ms	39668 KB	Output is correct
111	Correct	112 ms	39616 KB	Output is correct