답안 #622276

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
622276	2022-08-04T05:45:58 Z	jophyyjh	Global Warming (CEOI18_glo)	C++14	100 / 100	647 ms	43072 KB

/**
 * Notes during contest.
 * 
 * ------ A ------
 * Looks like a dp.
 * 
 * ------ B ------
 * I think i've seen sth similar on luogu. First, let's assume that d >= 0 and i'll
 * use the words "increase" & "decrease". If we wanna increase an interval by d, we
 * can greedily increase a suffix (instead of just an interval in the middle). If we
 * are to decrease an interval by d, we can greedily decrease a prefix. The two cases
 * are symmetric, so we can assume that one always increase a suffix by 0 <= d <= x.
 * And, if we're increasing a suffix, why don't we just do d=x? The rest is quite
 * straight-forward.
 * 
 * ------ C ------
 * For k_j = 0, we have to find the num of times each interval appeared. This can be
 * effectively done with str hashing. [S3] solved. [S1] is just brute-force: we can
 * do a O(n^2) for loop, iterating over all pairs of starting pos, naively comparing
 * the dist. of 2 substr. [S2] is a O(n^2) comparison between pairs of VALUES and
 * apply a difference array.
 * We're only looking for the num of mismatches. Let's compress the values (a_i:
 * 10^9 -> 10^4).
 * 
 * Time Complexity 1: O()
 * Time Complexity 2: O(n * log(n))
 * Time Complexity 3: O(n^2 + q) ([S1-2]), O(n)    (non-deterministic hashing)
 * Implementation 1             (Full solution, n * log(n) dp for LIS)
*/
 
#include <bits/stdc++.h>
 
typedef int64_t     int_t;
typedef std::vector<int_t>  vec;
 
const int_t INF = 0x3f3f3f3f3f3f3f;
 
 
int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);
 
    int_t n, x;
    std::cin >> n >> x;
    vec values(n);
    for (int_t k = 0; k < n; k++)
        std::cin >> values[k];
    
 
    vec left(n), right(n), min_end(n, INF);
    for (int_t k = 0; k < n; k++) {
        int_t t = -1;
        for (int_t step = n / 2 + 1; step >= 1; step /= 2) {
            while (t + step < n && values[k] > min_end[t + step])
                t += step;
        }
        min_end[t + 1] = values[k], left[k] = t + 2;
    }
    min_end.assign(n, -INF);
    for (int_t k = n - 1; k >= 0; k--) {
        int_t t = -1;
        for (int_t step = n / 2 + 1; step >= 1; step /= 2) {
            while (t + step < n && values[k] < min_end[t + step])
                t += step;
        }
        min_end[t + 1] = values[k], right[k] = t + 2;
    }
 
    vec vals(2 * n);
    for (int_t k = 0; k < n; k++)
        vals[2 * k] = values[k], vals[2 * k + 1] = values[k] + x;
    std::sort(vals.begin(), vals.end());
    std::map<int_t, int_t> compress;    // compressing index
    for (int_t k = 0; k < 2 * n; k++)
        compress[vals[k]] = k;
    int_t max_len = 0;
    vec seg_tree(4 * n, -INF);
    for (int_t k = 0; k < n; k++) {     // k: first index of our suffix
        int_t upper = compress[values[k] + x];
        if (k > 0 && upper > 0) {
            int_t left_len = 0;
            for (int_t a = 0 + 2 * n, b = upper - 1 + 2 * n; a <= b; a /= 2, b /= 2) {
                if (a % 2 == 1)
                    left_len = std::max(left_len, seg_tree[a++]);
                if (b % 2 == 0)
                    left_len = std::max(left_len, seg_tree[b--]);
            }
            max_len = std::max(max_len, left_len + right[k]);
        }
        for (int_t pt = compress[values[k]] + 2 * n; pt > 0; pt /= 2)
            seg_tree[pt] = std::max(seg_tree[pt], left[k]);
    }
    std::cout << max_len << '\n';
}

Subtask #1
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	256 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	1 ms	212 KB	Output is correct
10	Correct	1 ms	324 KB	Output is correct
11	Correct	1 ms	212 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	1 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	256 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	1 ms	212 KB	Output is correct
10	Correct	1 ms	324 KB	Output is correct
11	Correct	1 ms	212 KB	Output is correct
12	Correct	1 ms	212 KB	Output is correct
13	Correct	1 ms	324 KB	Output is correct
14	Correct	1 ms	212 KB	Output is correct
15	Correct	1 ms	320 KB	Output is correct
16	Correct	1 ms	212 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct

Subtask #3
13.0 / 13.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	256 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	1 ms	212 KB	Output is correct
10	Correct	1 ms	324 KB	Output is correct
11	Correct	1 ms	212 KB	Output is correct
12	Correct	1 ms	212 KB	Output is correct
13	Correct	1 ms	324 KB	Output is correct
14	Correct	1 ms	212 KB	Output is correct
15	Correct	1 ms	320 KB	Output is correct
16	Correct	1 ms	212 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	1 ms	468 KB	Output is correct
20	Correct	1 ms	460 KB	Output is correct
21	Correct	2 ms	468 KB	Output is correct
22	Correct	1 ms	468 KB	Output is correct
23	Correct	1 ms	468 KB	Output is correct
24	Correct	1 ms	460 KB	Output is correct
25	Correct	2 ms	340 KB	Output is correct
26	Correct	1 ms	476 KB	Output is correct

Subtask #4
10.0 / 10.0

#	결과	실행 시간	메모리	Grader output
1	Correct	379 ms	30412 KB	Output is correct
2	Correct	401 ms	30532 KB	Output is correct
3	Correct	369 ms	30440 KB	Output is correct
4	Correct	402 ms	30368 KB	Output is correct
5	Correct	162 ms	23364 KB	Output is correct

Subtask #5
20.0 / 20.0

#	결과	실행 시간	메모리	Grader output
1	Correct	72 ms	10932 KB	Output is correct
2	Correct	79 ms	10984 KB	Output is correct
3	Correct	78 ms	10932 KB	Output is correct
4	Correct	37 ms	7664 KB	Output is correct
5	Correct	1 ms	320 KB	Output is correct
6	Correct	38 ms	7660 KB	Output is correct
7	Correct	55 ms	9944 KB	Output is correct

Subtask #6
17.0 / 17.0

#	결과	실행 시간	메모리	Grader output
1	Correct	256 ms	21704 KB	Output is correct
2	Correct	266 ms	21652 KB	Output is correct
3	Correct	647 ms	42868 KB	Output is correct
4	Correct	196 ms	29556 KB	Output is correct
5	Correct	130 ms	21260 KB	Output is correct
6	Correct	219 ms	40132 KB	Output is correct
7	Correct	229 ms	40872 KB	Output is correct
8	Correct	166 ms	21660 KB	Output is correct

Subtask #7
25.0 / 25.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	256 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	1 ms	212 KB	Output is correct
10	Correct	1 ms	324 KB	Output is correct
11	Correct	1 ms	212 KB	Output is correct
12	Correct	1 ms	212 KB	Output is correct
13	Correct	1 ms	324 KB	Output is correct
14	Correct	1 ms	212 KB	Output is correct
15	Correct	1 ms	320 KB	Output is correct
16	Correct	1 ms	212 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	1 ms	468 KB	Output is correct
20	Correct	1 ms	460 KB	Output is correct
21	Correct	2 ms	468 KB	Output is correct
22	Correct	1 ms	468 KB	Output is correct
23	Correct	1 ms	468 KB	Output is correct
24	Correct	1 ms	460 KB	Output is correct
25	Correct	2 ms	340 KB	Output is correct
26	Correct	1 ms	476 KB	Output is correct
27	Correct	379 ms	30412 KB	Output is correct
28	Correct	401 ms	30532 KB	Output is correct
29	Correct	369 ms	30440 KB	Output is correct
30	Correct	402 ms	30368 KB	Output is correct
31	Correct	162 ms	23364 KB	Output is correct
32	Correct	72 ms	10932 KB	Output is correct
33	Correct	79 ms	10984 KB	Output is correct
34	Correct	78 ms	10932 KB	Output is correct
35	Correct	37 ms	7664 KB	Output is correct
36	Correct	1 ms	320 KB	Output is correct
37	Correct	38 ms	7660 KB	Output is correct
38	Correct	55 ms	9944 KB	Output is correct
39	Correct	256 ms	21704 KB	Output is correct
40	Correct	266 ms	21652 KB	Output is correct
41	Correct	647 ms	42868 KB	Output is correct
42	Correct	196 ms	29556 KB	Output is correct
43	Correct	130 ms	21260 KB	Output is correct
44	Correct	219 ms	40132 KB	Output is correct
45	Correct	229 ms	40872 KB	Output is correct
46	Correct	166 ms	21660 KB	Output is correct
47	Correct	214 ms	21652 KB	Output is correct
48	Correct	187 ms	21648 KB	Output is correct
49	Correct	502 ms	42956 KB	Output is correct
50	Correct	173 ms	29624 KB	Output is correct
51	Correct	153 ms	22312 KB	Output is correct
52	Correct	231 ms	29772 KB	Output is correct
53	Correct	246 ms	42300 KB	Output is correct
54	Correct	253 ms	43072 KB	Output is correct
55	Correct	315 ms	38748 KB	Output is correct

답안 #622276

Compilation message

Subtask #1 5.0 / 5.0

Subtask #2 10.0 / 10.0

Subtask #3 13.0 / 13.0

Subtask #4 10.0 / 10.0

Subtask #5 20.0 / 20.0

Subtask #6 17.0 / 17.0

Subtask #7 25.0 / 25.0

Subtask #1
5.0 / 5.0

Subtask #2
10.0 / 10.0

Subtask #3
13.0 / 13.0

Subtask #4
10.0 / 10.0

Subtask #5
20.0 / 20.0

Subtask #6
17.0 / 17.0

Subtask #7
25.0 / 25.0