답안 #612549

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
612549	2022-07-29T17:21:50 Z	hibiki	Event Hopping (BOI22_events)	C++11	100 / 100	869 ms	54464 KB

events

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

#define pb push_back
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()

int n, q;
int pw2[20];
pair<int,int> a[100005];
int spa[100005][20];

set<int> re;
vector<int> re2;
map<int, int> en, de;
struct node
{
    pair<int, int> mn = {2e9, -1};
    node *l = NULL, *r = NULL;
} *root;

node* build(int l, int r)
{
    node *ptr = new node();
    if(l == r) return ptr;
    int mid = (l + r) / 2;
    ptr->l = build(l, mid);
    ptr->r = build(mid + 1, r);
    return ptr;
}

void up(node *ptr, int l, int r, pair<int, int> val, int po)
{
    ptr->mn = min(ptr->mn, val);
    if(l == r) return ;
    int mid = (l + r) / 2;
    if(po <= mid) up(ptr->l, l, mid, val, po);
    else up(ptr->r, mid + 1, r, val, po);
}

pair<int, int> que(node *ptr, int l, int r, int ll, int rr)
{
    if(ll <= l && r <= rr) return ptr->mn;
    if(r < ll || rr < l) return {2e9, -1};
    int mid = (l + r) / 2;
    return min(que(ptr->l, l, mid, ll, rr), que(ptr->r, mid + 1, r, ll, rr));
}

int main()
{
    // freopen("test.in", "r", stdin);
    // freopen("test.out", "w", stdout);
    pw2[0] = 1;
    for(int i = 1; i < 20; i++)
        pw2[i] = pw2[i - 1] * 2;
    scanf("%d %d", &n, &q);
    for(int i = 0; i < n; i++)
    {
        scanf("%d %d", &a[i].f, &a[i].s);
        re.insert(a[i].f);
        re.insert(a[i].s);
    }
    for(auto val: re)
    {
        en[val] = sz(re2);
        de[sz(re2)] = val;
        re2.pb(val);
    }
    root = build(0, sz(re2));
    for(int i = 0; i < n; i++)
        up(root, 0, sz(re2), {a[i].f, i}, en[a[i].s]);
    for(int i = 0; i < n; i++)
    {
        pair<int, int> ret = que(root, 0, sz(re2), en[a[i].f], en[a[i].s]);
        if(ret.s == i || ret.f == a[i].f)
            spa[i][0] = -1;
        else
            spa[i][0] = ret.s;
        // printf("p: %d %d\n",i, spa[i][0]);
    }

    for(int j = 1; j < 20; j++)
        for(int i = 0; i < n; i++)
            if(spa[i][j - 1] != -1)
                spa[i][j] = spa[spa[i][j - 1]][j - 1];
            else
                spa[i][j] = -1;

    for(int i = 0; i < q; i++)
    {
        int s, t;
        scanf("%d %d", &s, &t);
        s--, t--;
        if(s == t)
            printf("0\n");
        else if(a[t].f <= a[s].s && a[s].s <= a[t].s)
            printf("1\n");
        else if(a[s].s > a[t].s)
            printf("impossible\n");
        else
        {
            int ans = 0, cur = t;
            for(int j = 19; j >= 0; j--)
            {
                if(spa[cur][j] != -1 && a[s].s < a[spa[cur][j]].f)
                {
                    ans += pw2[j];
                    cur = spa[cur][j];
                }
            }
            if(spa[cur][0] != -1 && a[spa[cur][0]].f <= a[s].s)
                printf("%d\n", ans + 2);
            else
                printf("impossible\n");
        }
    }
    return 0;
}

/*
8 5
1 2
3 4
1 5
6 7
5 10
10 20
15 20
999999999 1000000000
1 6
1 7
2 4
3 3
5 8
*/

Compilation message

events.cpp: In function 'int main()':
events.cpp:58:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |     scanf("%d %d", &n, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~~
events.cpp:61:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         scanf("%d %d", &a[i].f, &a[i].s);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:94:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         scanf("%d %d", &s, &t);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1

10.0 / 10.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	333 ms	30536 KB	Output is correct
3	Correct	398 ms	30420 KB	Output is correct
4	Correct	401 ms	30424 KB	Output is correct
5	Correct	411 ms	32580 KB	Output is correct
6	Correct	412 ms	37304 KB	Output is correct
7	Correct	440 ms	38032 KB	Output is correct
8	Correct	452 ms	54464 KB	Output is correct
9	Correct	483 ms	54424 KB	Output is correct
10	Correct	368 ms	33712 KB	Output is correct
11	Correct	429 ms	41852 KB	Output is correct
12	Correct	179 ms	32992 KB	Output is correct

Subtask #2

10.0 / 10.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	0 ms	212 KB	Output is correct
3	Correct	2 ms	596 KB	Output is correct
4	Correct	2 ms	596 KB	Output is correct
5	Correct	2 ms	596 KB	Output is correct
6	Correct	2 ms	596 KB	Output is correct
7	Correct	3 ms	724 KB	Output is correct
8	Correct	3 ms	724 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct

Subtask #3

15.0 / 15.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	0 ms	212 KB	Output is correct
3	Correct	2 ms	596 KB	Output is correct
4	Correct	2 ms	596 KB	Output is correct
5	Correct	2 ms	596 KB	Output is correct
6	Correct	2 ms	596 KB	Output is correct
7	Correct	3 ms	724 KB	Output is correct
8	Correct	3 ms	724 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct
10	Correct	1 ms	212 KB	Output is correct
11	Correct	1 ms	212 KB	Output is correct
12	Correct	2 ms	596 KB	Output is correct
13	Correct	3 ms	668 KB	Output is correct
14	Correct	3 ms	596 KB	Output is correct
15	Correct	2 ms	596 KB	Output is correct
16	Correct	3 ms	724 KB	Output is correct
17	Correct	4 ms	724 KB	Output is correct
18	Correct	1 ms	340 KB	Output is correct
19	Correct	41 ms	3488 KB	Output is correct
20	Correct	42 ms	3232 KB	Output is correct
21	Correct	43 ms	3524 KB	Output is correct
22	Correct	31 ms	3612 KB	Output is correct
23	Correct	39 ms	4424 KB	Output is correct
24	Correct	33 ms	4372 KB	Output is correct
25	Correct	46 ms	4116 KB	Output is correct

Subtask #4

15.0 / 15.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	0 ms	212 KB	Output is correct
3	Correct	2 ms	596 KB	Output is correct
4	Correct	2 ms	596 KB	Output is correct
5	Correct	2 ms	596 KB	Output is correct
6	Correct	2 ms	596 KB	Output is correct
7	Correct	3 ms	724 KB	Output is correct
8	Correct	3 ms	724 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct
10	Correct	0 ms	212 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	2 ms	624 KB	Output is correct
13	Correct	2 ms	632 KB	Output is correct
14	Correct	2 ms	596 KB	Output is correct
15	Correct	2 ms	596 KB	Output is correct
16	Correct	2 ms	724 KB	Output is correct
17	Correct	2 ms	724 KB	Output is correct
18	Correct	1 ms	324 KB	Output is correct
19	Correct	341 ms	30204 KB	Output is correct
20	Correct	297 ms	30708 KB	Output is correct
21	Correct	324 ms	31332 KB	Output is correct
22	Correct	383 ms	38920 KB	Output is correct
23	Correct	544 ms	52164 KB	Output is correct
24	Correct	590 ms	52300 KB	Output is correct
25	Correct	32 ms	10060 KB	Output is correct

Subtask #5

20.0 / 20.0

#	결과	실행 시간	메모리	Grader output
1	Correct	363 ms	30416 KB	Output is correct
2	Correct	375 ms	30436 KB	Output is correct
3	Correct	433 ms	30420 KB	Output is correct
4	Correct	521 ms	51788 KB	Output is correct
5	Correct	414 ms	30856 KB	Output is correct
6	Correct	623 ms	51472 KB	Output is correct
7	Correct	641 ms	51508 KB	Output is correct
8	Correct	609 ms	51616 KB	Output is correct
9	Correct	670 ms	50728 KB	Output is correct
10	Correct	764 ms	51152 KB	Output is correct
11	Correct	737 ms	51068 KB	Output is correct
12	Correct	869 ms	51348 KB	Output is correct

Subtask #6

30.0 / 30.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	333 ms	30536 KB	Output is correct
3	Correct	398 ms	30420 KB	Output is correct
4	Correct	401 ms	30424 KB	Output is correct
5	Correct	411 ms	32580 KB	Output is correct
6	Correct	412 ms	37304 KB	Output is correct
7	Correct	440 ms	38032 KB	Output is correct
8	Correct	452 ms	54464 KB	Output is correct
9	Correct	483 ms	54424 KB	Output is correct
10	Correct	368 ms	33712 KB	Output is correct
11	Correct	429 ms	41852 KB	Output is correct
12	Correct	179 ms	32992 KB	Output is correct
13	Correct	1 ms	212 KB	Output is correct
14	Correct	0 ms	212 KB	Output is correct
15	Correct	2 ms	596 KB	Output is correct
16	Correct	2 ms	596 KB	Output is correct
17	Correct	2 ms	596 KB	Output is correct
18	Correct	2 ms	596 KB	Output is correct
19	Correct	3 ms	724 KB	Output is correct
20	Correct	3 ms	724 KB	Output is correct
21	Correct	1 ms	340 KB	Output is correct
22	Correct	1 ms	212 KB	Output is correct
23	Correct	1 ms	212 KB	Output is correct
24	Correct	2 ms	596 KB	Output is correct
25	Correct	3 ms	668 KB	Output is correct
26	Correct	3 ms	596 KB	Output is correct
27	Correct	2 ms	596 KB	Output is correct
28	Correct	3 ms	724 KB	Output is correct
29	Correct	4 ms	724 KB	Output is correct
30	Correct	1 ms	340 KB	Output is correct
31	Correct	41 ms	3488 KB	Output is correct
32	Correct	42 ms	3232 KB	Output is correct
33	Correct	43 ms	3524 KB	Output is correct
34	Correct	31 ms	3612 KB	Output is correct
35	Correct	39 ms	4424 KB	Output is correct
36	Correct	33 ms	4372 KB	Output is correct
37	Correct	46 ms	4116 KB	Output is correct
38	Correct	0 ms	212 KB	Output is correct
39	Correct	0 ms	212 KB	Output is correct
40	Correct	2 ms	624 KB	Output is correct
41	Correct	2 ms	632 KB	Output is correct
42	Correct	2 ms	596 KB	Output is correct
43	Correct	2 ms	596 KB	Output is correct
44	Correct	2 ms	724 KB	Output is correct
45	Correct	2 ms	724 KB	Output is correct
46	Correct	1 ms	324 KB	Output is correct
47	Correct	341 ms	30204 KB	Output is correct
48	Correct	297 ms	30708 KB	Output is correct
49	Correct	324 ms	31332 KB	Output is correct
50	Correct	383 ms	38920 KB	Output is correct
51	Correct	544 ms	52164 KB	Output is correct
52	Correct	590 ms	52300 KB	Output is correct
53	Correct	32 ms	10060 KB	Output is correct
54	Correct	363 ms	30416 KB	Output is correct
55	Correct	375 ms	30436 KB	Output is correct
56	Correct	433 ms	30420 KB	Output is correct
57	Correct	521 ms	51788 KB	Output is correct
58	Correct	414 ms	30856 KB	Output is correct
59	Correct	623 ms	51472 KB	Output is correct
60	Correct	641 ms	51508 KB	Output is correct
61	Correct	609 ms	51616 KB	Output is correct
62	Correct	670 ms	50728 KB	Output is correct
63	Correct	764 ms	51152 KB	Output is correct
64	Correct	737 ms	51068 KB	Output is correct
65	Correct	869 ms	51348 KB	Output is correct
66	Correct	1 ms	212 KB	Output is correct
67	Correct	444 ms	33200 KB	Output is correct
68	Correct	445 ms	33188 KB	Output is correct
69	Correct	458 ms	33252 KB	Output is correct
70	Correct	501 ms	35356 KB	Output is correct
71	Correct	493 ms	37296 KB	Output is correct
72	Correct	468 ms	37908 KB	Output is correct
73	Correct	566 ms	54400 KB	Output is correct
74	Correct	499 ms	54444 KB	Output is correct
75	Correct	382 ms	33616 KB	Output is correct
76	Correct	462 ms	41888 KB	Output is correct
77	Correct	188 ms	33028 KB	Output is correct
78	Correct	0 ms	212 KB	Output is correct
79	Correct	2 ms	624 KB	Output is correct
80	Correct	2 ms	616 KB	Output is correct
81	Correct	2 ms	596 KB	Output is correct
82	Correct	2 ms	596 KB	Output is correct
83	Correct	2 ms	724 KB	Output is correct
84	Correct	3 ms	728 KB	Output is correct
85	Correct	1 ms	340 KB	Output is correct
86	Correct	43 ms	3480 KB	Output is correct
87	Correct	41 ms	3276 KB	Output is correct
88	Correct	41 ms	3528 KB	Output is correct
89	Correct	36 ms	3572 KB	Output is correct
90	Correct	41 ms	4444 KB	Output is correct
91	Correct	33 ms	4428 KB	Output is correct
92	Correct	44 ms	4080 KB	Output is correct
93	Correct	373 ms	31452 KB	Output is correct
94	Correct	342 ms	30692 KB	Output is correct
95	Correct	335 ms	31428 KB	Output is correct
96	Correct	421 ms	39108 KB	Output is correct
97	Correct	553 ms	52200 KB	Output is correct
98	Correct	613 ms	52284 KB	Output is correct
99	Correct	41 ms	10136 KB	Output is correct
100	Correct	698 ms	54112 KB	Output is correct
101	Correct	607 ms	54196 KB	Output is correct
102	Correct	605 ms	54288 KB	Output is correct
103	Correct	635 ms	53740 KB	Output is correct
104	Correct	660 ms	53356 KB	Output is correct
105	Correct	584 ms	53808 KB	Output is correct
106	Correct	303 ms	27580 KB	Output is correct
107	Correct	360 ms	32628 KB	Output is correct
108	Correct	426 ms	33412 KB	Output is correct
109	Correct	368 ms	33392 KB	Output is correct
110	Correct	612 ms	54100 KB	Output is correct
111	Correct	617 ms	54160 KB	Output is correct