oj.uz

Submission #1080768

# Submission time Handle Problem Language Result Execution time Memory
1080768 2024-08-29T13:54:03 Z andrei_iorgulescu Ancient Books (IOI17_books) C++14
100 / 100
 277 ms 238796 KB 
#include <bits/stdc++.h>
#include "books.h"
#warning That's not FB, that's my FB

using namespace std;

using ll = long long;

int inf = 1e9;

int n, s;
int p[1000005], pos[1000005];
vector<vector<int>> cyc;
vector<int> cur;
bool viz[1000005];

void dfs(int nod)
{
    viz[nod] = true;
    cur.push_back(nod);
    if (!viz[p[nod]])
        dfs(p[nod]);
}

int vmin[1000005], vmax[1000005];
int rmq_min[21][1000005], rmq_max[21][1000005];
int lg[1000005];

void build()
{
    for (int i = 2; i <= n; i++)
        lg[i] = 1 + lg[i / 2];
    for (int i = 1; i <= n; i++)
    {
        rmq_min[0][i] = vmin[i];
        rmq_max[0][i] = vmax[i];
    }
    for (int j = 1; j <= lg[n]; j++)
    {
        for (int i = 1; i <= n - (1 << j) + 1; i++)
        {
            rmq_min[j][i] = min(rmq_min[j - 1][i], rmq_min[j - 1][i + (1 << (j - 1))]);
            rmq_max[j][i] = max(rmq_max[j - 1][i], rmq_max[j - 1][i + (1 << (j - 1))]);
        }
    }
}

int qmin(int l, int r)
{
    int lgg = lg[r - l + 1];
    return min(rmq_min[lgg][l], rmq_min[lgg][r - (1 << lgg) + 1]);
}

int qmax(int l, int r)
{
    int lgg = lg[r - l + 1];
    return max(rmq_max[lgg][l], rmq_max[lgg][r - (1 << lgg) + 1]);
}

pair<int,int> query(int l, int r)
{
    pair<int,int> uf = {qmin(l,r),qmax(l,r)};
    return uf;
}

pair<int,int> f(pair<int,int> pos)
{
    while (true)
    {
        pair<int,int> repos = query(pos.first,pos.second);
        if (repos.first == pos.first and repos.second == pos.second)
            break;
        pos = repos;
    }
    return pos;
}

int get_cl(pair<int,int> pos)
{
    int cst = 0;
    int inip = pos.second;
    while (pos.second == inip and pos.first != 1)
    {
        cst++;
        pos.first--;
        pos = f(pos);
    }
    if (pos.second == inip)
        return inf;
    return cst;
}

int get_cr(pair<int,int> pos)
{
    int cst = 0;
    int inip = pos.first;
    while (pos.first == inip and pos.second != n)
    {
        cst++;
        pos.second++;
        pos = f(pos);
    }
    if (pos.first == inip)
        return inf;
    return cst;
}

ll minimum_walk(vector<int> PERM, int STR)
{
    cyc.clear();
    memset(viz,0,sizeof(viz));
    n = PERM.size();
    for (int i = 1; i <= n; i++)
        p[i] = PERM[i - 1] + 1, pos[p[i]] = i;
    s = STR + 1;
    for (int i = 1; i <= n; i++)
    {
        if (!viz[i])
        {
            cur.clear();
            dfs(i);
            cyc.push_back(cur);
        }
    }
    for (auto it : cyc)
    {
        sort(it.begin(), it.end());
        for (auto itt : it)
            vmin[itt] = it[0], vmax[itt] = it.back();
    }
    build();
    ll ans = 0;
    for (int i = 1; i <= n; i++)
        ans += abs(i - p[i]);
    int pzz = 1;
    while (pzz < s and p[pzz] == pzz)
        ans -= 2, pzz++;
    pzz = n;
    while (pzz > s and p[pzz] == pzz)
        ans -= 2, pzz--;
    pair<int,int> pos = f({s,s});
    while (pos.first != 1 or pos.second != n)
    {
        int cl = get_cl(pos), cr = get_cr(pos);
        if (cl == inf)
        {
            while (pos.first != 1)
            {
                ans += 2;
                pos.first--;
                pos = f(pos);
            }
            while (pos.second != n)
            {
                ans += 2;
                pos.second++;
                pos = f(pos);
            }
        }
        else
        {
            if (cl <= cr)
            {
                for (int i = 1; i <= cl; i++)
                {
                    ans += 2;
                    pos.first--;
                    pos = f(pos);
                }
            }
            else
            {
                for (int i = 1; i <= cr; i++)
                {
                    ans += 2;
                    pos.second++;
                    pos = f(pos);
                }
            }
        }
    }
    return ans;
}

/**
doamne cate try-uri pana sa ajung la greedy-ul corect
daca faceam asta la cf era atat de over

In fine, eu mereu domin un interval [L R] cu prop ca f(L, R) = (L, R)
f(L, R) = (L, R) daca nu exista vreun i in (L R) care sa faca parte dintr-un ciclu care contine un j inn afara (L R)
Altfel f(L, R) = f(intv reunit cu intervalul ciclului aluia kind of stuff), idk doar un aint de minime si maxime

Acum, din (L, R) tu poti plati 2 bani ca sa faci artificial L-- sau R++
Fie cL = nr minim de mutari pe stanga astfel incat daca le faci, te extinzi pana la urma si in dreapta
cR = nr minim de mutari in dreapta astfel incat pana la urma te extinzi in stanga

Proof penal => e optim sa faci mutari in directia cu costul minim (adica faci min(cL, cR) mutari intr-o directie si vezi unde dai)
Ma rog, daca cL = cR = inf (nu poate fi doar una inf si una nu, ofc), spamezi mutari in ambele parti pana ajungi la capat

In fine, la final scazi 2 * (marimea sufixului de p[i] = i + marimea prefixului de p[i] = i)

Kinda se reduce la a gasi cL si cR eficient... chestia funny e ca nu trebuie vreo structura complicata
Gen, daca doar simulezi, oricum mereu te extinzi cu 1 intr-o parte, deci daca faci O(k) query-uri de aint, se va extinde (L, R) la final O(k)
Deci tot O(NlogN) iese sau cv de genul

Ce boti oamenii ca au bagat asa putini 50 -> 100
**/

Compilation message

books.cpp:3:2: warning: #warning That's not FB, that's my FB [-Wcpp]
    3 | #warning That's not FB, that's my FB
      |  ^~~~~~~

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1368 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 1 ms 1372 KB Output is correct
5 Correct 1 ms 1476 KB Output is correct
6 Correct 1 ms 1372 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 1372 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 1 ms 1372 KB Output is correct
11 Correct 1 ms 1372 KB Output is correct
12 Correct 1 ms 1372 KB Output is correct
13 Correct 1 ms 1372 KB Output is correct
14 Correct 1 ms 1368 KB Output is correct
15 Correct 1 ms 1372 KB Output is correct
16 Correct 1 ms 1372 KB Output is correct
17 Correct 1 ms 1372 KB Output is correct
18 Correct 1 ms 1372 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1368 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 1 ms 1372 KB Output is correct
5 Correct 1 ms 1476 KB Output is correct
6 Correct 1 ms 1372 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 1372 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 1 ms 1372 KB Output is correct
11 Correct 1 ms 1372 KB Output is correct
12 Correct 1 ms 1372 KB Output is correct
13 Correct 1 ms 1372 KB Output is correct
14 Correct 1 ms 1368 KB Output is correct
15 Correct 1 ms 1372 KB Output is correct
16 Correct 1 ms 1372 KB Output is correct
17 Correct 1 ms 1372 KB Output is correct
18 Correct 1 ms 1372 KB Output is correct
19 Correct 1 ms 1624 KB Output is correct
20 Correct 1 ms 1628 KB Output is correct
21 Correct 1 ms 1628 KB Output is correct
22 Correct 1 ms 1624 KB Output is correct
23 Correct 1 ms 1628 KB Output is correct
24 Correct 1 ms 1628 KB Output is correct
25 Correct 1 ms 1624 KB Output is correct
26 Correct 1 ms 1628 KB Output is correct
27 Correct 1 ms 1628 KB Output is correct
28 Correct 1 ms 1628 KB Output is correct
29 Correct 2 ms 1628 KB Output is correct

Subtask #3
28.0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1368 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 1 ms 1372 KB Output is correct
5 Correct 1 ms 1476 KB Output is correct
6 Correct 1 ms 1372 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 1372 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 1 ms 1372 KB Output is correct
11 Correct 1 ms 1372 KB Output is correct
12 Correct 1 ms 1372 KB Output is correct
13 Correct 1 ms 1372 KB Output is correct
14 Correct 1 ms 1368 KB Output is correct
15 Correct 1 ms 1372 KB Output is correct
16 Correct 1 ms 1372 KB Output is correct
17 Correct 1 ms 1372 KB Output is correct
18 Correct 1 ms 1372 KB Output is correct
19 Correct 1 ms 1624 KB Output is correct
20 Correct 1 ms 1628 KB Output is correct
21 Correct 1 ms 1628 KB Output is correct
22 Correct 1 ms 1624 KB Output is correct
23 Correct 1 ms 1628 KB Output is correct
24 Correct 1 ms 1628 KB Output is correct
25 Correct 1 ms 1624 KB Output is correct
26 Correct 1 ms 1628 KB Output is correct
27 Correct 1 ms 1628 KB Output is correct
28 Correct 1 ms 1628 KB Output is correct
29 Correct 2 ms 1628 KB Output is correct
30 Correct 277 ms 216040 KB Output is correct
31 Correct 254 ms 202488 KB Output is correct
32 Correct 250 ms 238692 KB Output is correct
33 Correct 230 ms 221896 KB Output is correct
34 Correct 240 ms 221900 KB Output is correct
35 Correct 221 ms 214220 KB Output is correct
36 Correct 195 ms 199452 KB Output is correct
37 Correct 196 ms 189188 KB Output is correct
38 Correct 237 ms 188272 KB Output is correct
39 Correct 197 ms 188240 KB Output is correct
40 Correct 269 ms 189236 KB Output is correct
41 Correct 248 ms 200604 KB Output is correct
42 Correct 269 ms 193804 KB Output is correct
43 Correct 228 ms 224508 KB Output is correct

Subtask #4
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1628 KB Output is correct
2 Correct 1 ms 1732 KB Output is correct
3 Correct 1 ms 1624 KB Output is correct
4 Correct 1 ms 1724 KB Output is correct
5 Correct 1 ms 1628 KB Output is correct
6 Correct 1 ms 1628 KB Output is correct
7 Correct 1 ms 1628 KB Output is correct
8 Correct 1 ms 1628 KB Output is correct
9 Correct 1 ms 1628 KB Output is correct
10 Correct 1 ms 1628 KB Output is correct
11 Correct 1 ms 1628 KB Output is correct
12 Correct 1 ms 1624 KB Output is correct
13 Correct 2 ms 1628 KB Output is correct
14 Correct 1 ms 1668 KB Output is correct
15 Correct 1 ms 1628 KB Output is correct
16 Correct 1 ms 1628 KB Output is correct
17 Correct 1 ms 1628 KB Output is correct
18 Correct 1 ms 1628 KB Output is correct
19 Correct 1 ms 1628 KB Output is correct
20 Correct 1 ms 1628 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1368 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 1 ms 1372 KB Output is correct
5 Correct 1 ms 1476 KB Output is correct
6 Correct 1 ms 1372 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 1372 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 1 ms 1372 KB Output is correct
11 Correct 1 ms 1372 KB Output is correct
12 Correct 1 ms 1372 KB Output is correct
13 Correct 1 ms 1372 KB Output is correct
14 Correct 1 ms 1368 KB Output is correct
15 Correct 1 ms 1372 KB Output is correct
16 Correct 1 ms 1372 KB Output is correct
17 Correct 1 ms 1372 KB Output is correct
18 Correct 1 ms 1372 KB Output is correct
19 Correct 1 ms 1624 KB Output is correct
20 Correct 1 ms 1628 KB Output is correct
21 Correct 1 ms 1628 KB Output is correct
22 Correct 1 ms 1624 KB Output is correct
23 Correct 1 ms 1628 KB Output is correct
24 Correct 1 ms 1628 KB Output is correct
25 Correct 1 ms 1624 KB Output is correct
26 Correct 1 ms 1628 KB Output is correct
27 Correct 1 ms 1628 KB Output is correct
28 Correct 1 ms 1628 KB Output is correct
29 Correct 2 ms 1628 KB Output is correct
30 Correct 277 ms 216040 KB Output is correct
31 Correct 254 ms 202488 KB Output is correct
32 Correct 250 ms 238692 KB Output is correct
33 Correct 230 ms 221896 KB Output is correct
34 Correct 240 ms 221900 KB Output is correct
35 Correct 221 ms 214220 KB Output is correct
36 Correct 195 ms 199452 KB Output is correct
37 Correct 196 ms 189188 KB Output is correct
38 Correct 237 ms 188272 KB Output is correct
39 Correct 197 ms 188240 KB Output is correct
40 Correct 269 ms 189236 KB Output is correct
41 Correct 248 ms 200604 KB Output is correct
42 Correct 269 ms 193804 KB Output is correct
43 Correct 228 ms 224508 KB Output is correct
44 Correct 1 ms 1628 KB Output is correct
45 Correct 1 ms 1732 KB Output is correct
46 Correct 1 ms 1624 KB Output is correct
47 Correct 1 ms 1724 KB Output is correct
48 Correct 1 ms 1628 KB Output is correct
49 Correct 1 ms 1628 KB Output is correct
50 Correct 1 ms 1628 KB Output is correct
51 Correct 1 ms 1628 KB Output is correct
52 Correct 1 ms 1628 KB Output is correct
53 Correct 1 ms 1628 KB Output is correct
54 Correct 1 ms 1628 KB Output is correct
55 Correct 1 ms 1624 KB Output is correct
56 Correct 2 ms 1628 KB Output is correct
57 Correct 1 ms 1668 KB Output is correct
58 Correct 1 ms 1628 KB Output is correct
59 Correct 1 ms 1628 KB Output is correct
60 Correct 1 ms 1628 KB Output is correct
61 Correct 1 ms 1628 KB Output is correct
62 Correct 1 ms 1628 KB Output is correct
63 Correct 1 ms 1628 KB Output is correct
64 Correct 207 ms 224048 KB Output is correct
65 Correct 215 ms 228096 KB Output is correct
66 Correct 231 ms 189192 KB Output is correct
67 Correct 211 ms 188508 KB Output is correct
68 Correct 19 ms 18964 KB Output is correct
69 Correct 17 ms 18288 KB Output is correct
70 Correct 19 ms 19216 KB Output is correct
71 Correct 20 ms 21000 KB Output is correct
72 Correct 22 ms 22016 KB Output is correct
73 Correct 24 ms 18072 KB Output is correct
74 Correct 219 ms 221748 KB Output is correct
75 Correct 223 ms 221812 KB Output is correct
76 Correct 258 ms 223944 KB Output is correct
77 Correct 212 ms 224372 KB Output is correct
78 Correct 206 ms 218568 KB Output is correct
79 Correct 240 ms 218596 KB Output is correct
80 Correct 243 ms 238796 KB Output is correct
81 Correct 207 ms 211224 KB Output is correct
82 Correct 206 ms 211172 KB Output is correct
83 Correct 216 ms 205036 KB Output is correct
84 Correct 230 ms 201248 KB Output is correct
85 Correct 184 ms 193700 KB Output is correct
86 Correct 210 ms 189960 KB Output is correct
87 Correct 238 ms 230132 KB Output is correct
88 Correct 232 ms 222412 KB Output is correct
89 Correct 206 ms 209044 KB Output is correct
90 Correct 235 ms 188684 KB Output is correct
91 Correct 189 ms 188240 KB Output is correct
92 Correct 212 ms 188240 KB Output is correct