Submission #597942

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
597942	2022-07-17T08:16:06 Z	maomao90	Event Hopping (BOI22_events)	C++17	100 / 100	147 ms	37288 KB

events

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

#define REP(i, j, k) for (int i = j; i < k; i++)
#define RREP(i, j, k) for (int i = j; i >= k; i--)

template <class T>
inline bool mnto(T &a, const T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T &a, const T b) {return a < b ? a = b, 1 : 0;}

typedef long long ll;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int) x.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vll;
typedef tuple<int, int, int> iii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int MAXN = 200005;
const int INF = 1000000005;
const ll LINF = 1000000000000000005;
const int MAXL = 20;

struct event {
    int s, e, i;
};

int n, q;
event se[MAXN];
int mp[MAXN];
int p[MAXL][MAXN];

int m;
int sp[MAXL][MAXN];
int qmn(int s, int e) {
    int k = 31 - __builtin_clz(e - s + 1);
    return min(sp[k][s], sp[k][e - (1 << k) + 1]);
}


int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> n >> q;
    REP (i, 1, n + 1) {
	cin >> se[i].s >> se[i].e;
	se[i].i = i;
    }
    sort(se + 1, se + n + 1, [&] (event l, event r) {
	    return l.s < r.s;
	    });
    vii disc;
    REP (i, 1, n + 1) {
	mp[se[i].i] = i;
	disc.pb({se[i].s, i});
	disc.pb({se[i].e, i + n});
    }
    sort(ALL(disc));
    int prv = -1;
    for (auto [x, i] : disc) {
	if (x != prv) {
	    prv = x;
	    m++;
	}
	if (i <= n) {
	    se[i].s = m;
	} else {
	    se[i - n].e = m;
	}
    }
    REP (i, 1, n + 1) {
	cerr << i << ": " << se[i].s << ' ' << se[i].e << '\n';
    }
    memset(p, -1, sizeof p);
    REP (i, 1, m + 1) {
	sp[0][i] = INF;
    }
    REP (i, 1, n + 1) {
	mnto(sp[0][se[i].e], i);
    }
    REP (k, 1, MAXL) {
	REP (i, 1, m + 1 - (1 << k - 1)) {
	    sp[k][i] = min(sp[k - 1][i], sp[k - 1][i + (1 << k - 1)]);
	}
    }
    REP (i, 1, n + 1) {
	p[0][i] = qmn(se[i].s, se[i].e);
	cerr << i << " -> " << p[0][i] << '\n';
    }
    /*
    REP (i, 1, n + 1) {
	ii mn = {INF, -1};
	REP (j, 1, n + 1) {
	    if (i == j) {
		continue;
	    }
	    if (se[i].s <= se[j].e && se[j].e <= se[i].e) {
		mnto(mn, {se[j].s, j});
	    }
	}
	p[0][i] = mn.SE;
	cerr << i << " -> " << p[0][i] << '\n';
    }
    */
    REP (k, 1, MAXL) {
	REP (i, 1, n + 1) {
	    if (p[k - 1][i] == -1) {
		p[k][i] = -1;
	    } else {
		p[k][i] = p[k - 1][p[k - 1][i]];
	    }
	}
    }
    while (q--) {
	int a, b; cin >> a >> b;
	a = mp[a]; b = mp[b];
	if (a == b) {
	    cout << 0 << '\n';
	    continue;
	}
	if (se[b].s <= se[a].e && se[a].e <= se[b].e) {
	    cout << 1 << '\n';
	    continue;
	}
	if (se[a].e > se[b].e) {
	    cout << "impossible\n";
	    continue;
	}
	int ans = 0;
	RREP (k, MAXL - 1, 0) {
	    if (p[k][b] == -1) {
		continue;
	    }
	    if (se[p[k][b]].s > se[a].e) {
		b = p[k][b];
		ans += 1 << k;
	    }
	}
	if (p[0][b] != -1 && se[p[0][b]].s <= se[a].e) {
	    ans += 2;
	    cout << ans << '\n';
	} else {
	    cout << "impossible\n";
	}
    }
    return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:93:29: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   93 |  REP (i, 1, m + 1 - (1 << k - 1)) {
      |                           ~~^~~
events.cpp:4:42: note: in definition of macro 'REP'
    4 | #define REP(i, j, k) for (int i = j; i < k; i++)
      |                                          ^
events.cpp:94:57: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   94 |      sp[k][i] = min(sp[k - 1][i], sp[k - 1][i + (1 << k - 1)]);
      |                                                       ~~^~~

Subtask #1

10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	15956 KB	Output is correct
2	Correct	77 ms	29480 KB	Output is correct
3	Correct	79 ms	29516 KB	Output is correct
4	Correct	88 ms	29380 KB	Output is correct
5	Correct	93 ms	30180 KB	Output is correct
6	Correct	103 ms	30968 KB	Output is correct
7	Correct	106 ms	31104 KB	Output is correct
8	Correct	86 ms	37220 KB	Output is correct
9	Correct	89 ms	37104 KB	Output is correct
10	Correct	143 ms	29868 KB	Output is correct
11	Correct	115 ms	32720 KB	Output is correct
12	Correct	60 ms	29180 KB	Output is correct

Subtask #2

10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	15956 KB	Output is correct
2	Correct	8 ms	15956 KB	Output is correct
3	Correct	7 ms	16096 KB	Output is correct
4	Correct	10 ms	16084 KB	Output is correct
5	Correct	10 ms	16084 KB	Output is correct
6	Correct	8 ms	16084 KB	Output is correct
7	Correct	9 ms	16100 KB	Output is correct
8	Correct	7 ms	16084 KB	Output is correct
9	Correct	9 ms	15964 KB	Output is correct

Subtask #3

15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	15956 KB	Output is correct
2	Correct	8 ms	15956 KB	Output is correct
3	Correct	7 ms	16096 KB	Output is correct
4	Correct	10 ms	16084 KB	Output is correct
5	Correct	10 ms	16084 KB	Output is correct
6	Correct	8 ms	16084 KB	Output is correct
7	Correct	9 ms	16100 KB	Output is correct
8	Correct	7 ms	16084 KB	Output is correct
9	Correct	9 ms	15964 KB	Output is correct
10	Correct	6 ms	15956 KB	Output is correct
11	Correct	7 ms	15940 KB	Output is correct
12	Correct	6 ms	16084 KB	Output is correct
13	Correct	8 ms	16084 KB	Output is correct
14	Correct	8 ms	16108 KB	Output is correct
15	Correct	8 ms	16084 KB	Output is correct
16	Correct	8 ms	16116 KB	Output is correct
17	Correct	8 ms	16100 KB	Output is correct
18	Correct	7 ms	15972 KB	Output is correct
19	Correct	39 ms	18124 KB	Output is correct
20	Correct	35 ms	17996 KB	Output is correct
21	Correct	51 ms	18344 KB	Output is correct
22	Correct	32 ms	18404 KB	Output is correct
23	Correct	29 ms	18468 KB	Output is correct
24	Correct	30 ms	18508 KB	Output is correct
25	Correct	45 ms	18168 KB	Output is correct

Subtask #4

15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	15956 KB	Output is correct
2	Correct	8 ms	15956 KB	Output is correct
3	Correct	7 ms	16096 KB	Output is correct
4	Correct	10 ms	16084 KB	Output is correct
5	Correct	10 ms	16084 KB	Output is correct
6	Correct	8 ms	16084 KB	Output is correct
7	Correct	9 ms	16100 KB	Output is correct
8	Correct	7 ms	16084 KB	Output is correct
9	Correct	9 ms	15964 KB	Output is correct
10	Correct	6 ms	15956 KB	Output is correct
11	Correct	6 ms	15956 KB	Output is correct
12	Correct	7 ms	16084 KB	Output is correct
13	Correct	9 ms	16052 KB	Output is correct
14	Correct	8 ms	16148 KB	Output is correct
15	Correct	9 ms	16060 KB	Output is correct
16	Correct	8 ms	16212 KB	Output is correct
17	Correct	7 ms	16212 KB	Output is correct
18	Correct	7 ms	15956 KB	Output is correct
19	Correct	51 ms	27716 KB	Output is correct
20	Correct	74 ms	26936 KB	Output is correct
21	Correct	72 ms	27460 KB	Output is correct
22	Correct	58 ms	30224 KB	Output is correct
23	Correct	56 ms	34884 KB	Output is correct
24	Correct	55 ms	35048 KB	Output is correct
25	Correct	52 ms	20372 KB	Output is correct

Subtask #5

20.0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	97 ms	29504 KB	Output is correct
2	Correct	72 ms	29512 KB	Output is correct
3	Correct	84 ms	29308 KB	Output is correct
4	Correct	89 ms	37096 KB	Output is correct
5	Correct	94 ms	29744 KB	Output is correct
6	Correct	121 ms	36784 KB	Output is correct
7	Correct	147 ms	36792 KB	Output is correct
8	Correct	105 ms	37032 KB	Output is correct
9	Correct	61 ms	34904 KB	Output is correct
10	Correct	83 ms	36532 KB	Output is correct
11	Correct	82 ms	36360 KB	Output is correct
12	Correct	78 ms	36448 KB	Output is correct

Subtask #6

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	15956 KB	Output is correct
2	Correct	77 ms	29480 KB	Output is correct
3	Correct	79 ms	29516 KB	Output is correct
4	Correct	88 ms	29380 KB	Output is correct
5	Correct	93 ms	30180 KB	Output is correct
6	Correct	103 ms	30968 KB	Output is correct
7	Correct	106 ms	31104 KB	Output is correct
8	Correct	86 ms	37220 KB	Output is correct
9	Correct	89 ms	37104 KB	Output is correct
10	Correct	143 ms	29868 KB	Output is correct
11	Correct	115 ms	32720 KB	Output is correct
12	Correct	60 ms	29180 KB	Output is correct
13	Correct	7 ms	15956 KB	Output is correct
14	Correct	8 ms	15956 KB	Output is correct
15	Correct	7 ms	16096 KB	Output is correct
16	Correct	10 ms	16084 KB	Output is correct
17	Correct	10 ms	16084 KB	Output is correct
18	Correct	8 ms	16084 KB	Output is correct
19	Correct	9 ms	16100 KB	Output is correct
20	Correct	7 ms	16084 KB	Output is correct
21	Correct	9 ms	15964 KB	Output is correct
22	Correct	6 ms	15956 KB	Output is correct
23	Correct	7 ms	15940 KB	Output is correct
24	Correct	6 ms	16084 KB	Output is correct
25	Correct	8 ms	16084 KB	Output is correct
26	Correct	8 ms	16108 KB	Output is correct
27	Correct	8 ms	16084 KB	Output is correct
28	Correct	8 ms	16116 KB	Output is correct
29	Correct	8 ms	16100 KB	Output is correct
30	Correct	7 ms	15972 KB	Output is correct
31	Correct	39 ms	18124 KB	Output is correct
32	Correct	35 ms	17996 KB	Output is correct
33	Correct	51 ms	18344 KB	Output is correct
34	Correct	32 ms	18404 KB	Output is correct
35	Correct	29 ms	18468 KB	Output is correct
36	Correct	30 ms	18508 KB	Output is correct
37	Correct	45 ms	18168 KB	Output is correct
38	Correct	6 ms	15956 KB	Output is correct
39	Correct	6 ms	15956 KB	Output is correct
40	Correct	7 ms	16084 KB	Output is correct
41	Correct	9 ms	16052 KB	Output is correct
42	Correct	8 ms	16148 KB	Output is correct
43	Correct	9 ms	16060 KB	Output is correct
44	Correct	8 ms	16212 KB	Output is correct
45	Correct	7 ms	16212 KB	Output is correct
46	Correct	7 ms	15956 KB	Output is correct
47	Correct	51 ms	27716 KB	Output is correct
48	Correct	74 ms	26936 KB	Output is correct
49	Correct	72 ms	27460 KB	Output is correct
50	Correct	58 ms	30224 KB	Output is correct
51	Correct	56 ms	34884 KB	Output is correct
52	Correct	55 ms	35048 KB	Output is correct
53	Correct	52 ms	20372 KB	Output is correct
54	Correct	97 ms	29504 KB	Output is correct
55	Correct	72 ms	29512 KB	Output is correct
56	Correct	84 ms	29308 KB	Output is correct
57	Correct	89 ms	37096 KB	Output is correct
58	Correct	94 ms	29744 KB	Output is correct
59	Correct	121 ms	36784 KB	Output is correct
60	Correct	147 ms	36792 KB	Output is correct
61	Correct	105 ms	37032 KB	Output is correct
62	Correct	61 ms	34904 KB	Output is correct
63	Correct	83 ms	36532 KB	Output is correct
64	Correct	82 ms	36360 KB	Output is correct
65	Correct	78 ms	36448 KB	Output is correct
66	Correct	7 ms	15956 KB	Output is correct
67	Correct	87 ms	29488 KB	Output is correct
68	Correct	81 ms	29412 KB	Output is correct
69	Correct	90 ms	29408 KB	Output is correct
70	Correct	77 ms	30284 KB	Output is correct
71	Correct	82 ms	30960 KB	Output is correct
72	Correct	92 ms	31132 KB	Output is correct
73	Correct	81 ms	37144 KB	Output is correct
74	Correct	75 ms	37288 KB	Output is correct
75	Correct	91 ms	29848 KB	Output is correct
76	Correct	134 ms	32696 KB	Output is correct
77	Correct	66 ms	29172 KB	Output is correct
78	Correct	6 ms	15956 KB	Output is correct
79	Correct	6 ms	16084 KB	Output is correct
80	Correct	7 ms	16064 KB	Output is correct
81	Correct	8 ms	16148 KB	Output is correct
82	Correct	7 ms	16084 KB	Output is correct
83	Correct	8 ms	16096 KB	Output is correct
84	Correct	7 ms	16212 KB	Output is correct
85	Correct	7 ms	15956 KB	Output is correct
86	Correct	40 ms	18116 KB	Output is correct
87	Correct	35 ms	18036 KB	Output is correct
88	Correct	38 ms	18292 KB	Output is correct
89	Correct	33 ms	18352 KB	Output is correct
90	Correct	30 ms	18480 KB	Output is correct
91	Correct	27 ms	18488 KB	Output is correct
92	Correct	31 ms	18136 KB	Output is correct
93	Correct	46 ms	27716 KB	Output is correct
94	Correct	52 ms	26964 KB	Output is correct
95	Correct	56 ms	27656 KB	Output is correct
96	Correct	50 ms	30404 KB	Output is correct
97	Correct	55 ms	35004 KB	Output is correct
98	Correct	52 ms	34976 KB	Output is correct
99	Correct	38 ms	20436 KB	Output is correct
100	Correct	106 ms	36876 KB	Output is correct
101	Correct	108 ms	36836 KB	Output is correct
102	Correct	91 ms	36948 KB	Output is correct
103	Correct	80 ms	36484 KB	Output is correct
104	Correct	96 ms	36080 KB	Output is correct
105	Correct	78 ms	36476 KB	Output is correct
106	Correct	89 ms	27204 KB	Output is correct
107	Correct	111 ms	28964 KB	Output is correct
108	Correct	109 ms	29616 KB	Output is correct
109	Correct	93 ms	29596 KB	Output is correct
110	Correct	86 ms	36748 KB	Output is correct
111	Correct	89 ms	36840 KB	Output is correct