Submission #464883

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
464883	2021-08-14T11:28:09 Z	blue	Ancient Books (IOI17_books)	C++17	50 / 100	224 ms	30660 KB

books

#include "books.h"
#include <vector>
#include <cstdlib>
#include <algorithm>
#include <iostream>
using namespace std;

const int maxN = 1'000'000;

const int ind_R = 1'000'005;
const int ind_L = -1;

const long long INF = 1'000'000'000'000'000'000LL;

int N;
vector<int> P;

int S;

int cycle_ind = -1;
vector<int> cycle(maxN, -1);
vector<int> L(maxN, ind_R);
vector<int> R(maxN, ind_L);

long long essential_cost = 0;

void extend(int& l, int& r) //[l, r] is extended fully except for the cycles of l and r
{
	int l_new = min(L[cycle[l]], L[cycle[r]]);
	int r_new = max(R[cycle[l]], R[cycle[r]]);

	// cerr << "ln = " << l_new << ", rn = " << r_new << '\n';

	while(l != l_new || r != r_new)
	{
		if(l != l_new)
		{
			l--;
			l_new = min(l_new, L[cycle[l]]);
			r_new = max(r_new, R[cycle[l]]);
		}

		if(r != r_new)
		{
			r++;
			l_new = min(l_new, L[cycle[r]]);
			r_new = max(r_new, R[cycle[r]]);
		}
	}
}

long long minimum_walk(vector<int> p, int s)
{
	N = p.size();
	P = p;
	S = s;

	int solve_L = S;
	int solve_R = S;

	for(int i = 0; i < N; i++)
	{
		essential_cost += abs(P[i] - i);

		if(P[i] != i)
		{
			solve_L = min(solve_L, i);
			solve_R = max(solve_R, i);
		}

		if(cycle[i] != -1) continue;

		cycle_ind++;

		int j = i;
		do
		{
			cycle[j] = cycle_ind;

			L[ cycle[j] ] = min(L[ cycle[j] ], j);
			R[ cycle[j] ] = max(R[ cycle[j] ], j);

			j = P[j];
		} while(j != i);
	}

	if(solve_L == S && solve_R == S) return 0;

	// for(int i = 0; i < N; i++) cerr << cycle[i] << ' ';
	// cerr << '\n';
	//
	// cerr << "solve range = " <<  solve_L << ' ' << solve_R << '\n';


	long long extra_cost = 0;

	int l = S;
	int r = S;
	// cerr << "l = " << l << ", r = " << r << '\n';
	extend(l, r);
	// cerr << "l = " << l << ", r = " << r << '\n';

	while(l != solve_L || r != solve_R)
	{
		bool S_cycle_exists = 0;

		long long left_cost = 0;
		int new_l;
		for(int i = l-1; i >= solve_L; i--)
		{
			if(R[ cycle[i] ] >= S)
			{
				S_cycle_exists = 1;
				left_cost = 2*(l - i);
				new_l = i;
				break;
			}
		}

		if(!S_cycle_exists) break;

		long long right_cost = 0;
		int new_r;
		for(int i = r+1; i <= solve_R; i++)
		{
			if(L[ cycle[i] ] <= S)
			{
				right_cost = 2*(i - r);
				new_r = i;
				break;
			}
		}

		extra_cost += min(left_cost, right_cost);
		l = new_l;
		r = new_r;
		extend(l, r);
	}

	for(int l2 = l-1; l2 >= solve_L; l2--)
	{
		if(l2 >= l) continue;
		if(R[ cycle[l2] ] == l2)
		{
			extra_cost += 2*(l - l2);
			l = l2;
			extend(l, r);
		}
	}

	for(int r2 = r+1; r2 <= solve_R; r2++)
	{
		if(r2 <= r) continue;
		if(L[ cycle[r2] ] == r2)
		{
			extra_cost += 2*(r2 - r);
			r = r2;
			extend(l, r);
		}
	}

	return essential_cost + extra_cost;
}

Compilation message

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:136:5: warning: 'new_r' may be used uninitialized in this function [-Wmaybe-uninitialized]
  136 |   r = new_r;
      |   ~~^~~~~~~

Subtask #1
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	11980 KB	Output is correct
2	Correct	6 ms	12060 KB	Output is correct
3	Correct	6 ms	11980 KB	Output is correct
4	Correct	8 ms	11980 KB	Output is correct
5	Correct	6 ms	11980 KB	Output is correct
6	Correct	7 ms	11980 KB	Output is correct
7	Correct	7 ms	11980 KB	Output is correct
8	Correct	7 ms	11980 KB	Output is correct
9	Correct	9 ms	11936 KB	Output is correct
10	Correct	7 ms	11980 KB	Output is correct
11	Correct	7 ms	11980 KB	Output is correct
12	Correct	7 ms	12056 KB	Output is correct
13	Correct	8 ms	11936 KB	Output is correct
14	Correct	7 ms	11980 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	8 ms	11980 KB	Output is correct
17	Correct	9 ms	11980 KB	Output is correct
18	Correct	7 ms	12052 KB	Output is correct

Subtask #2
10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	11980 KB	Output is correct
2	Correct	6 ms	12060 KB	Output is correct
3	Correct	6 ms	11980 KB	Output is correct
4	Correct	8 ms	11980 KB	Output is correct
5	Correct	6 ms	11980 KB	Output is correct
6	Correct	7 ms	11980 KB	Output is correct
7	Correct	7 ms	11980 KB	Output is correct
8	Correct	7 ms	11980 KB	Output is correct
9	Correct	9 ms	11936 KB	Output is correct
10	Correct	7 ms	11980 KB	Output is correct
11	Correct	7 ms	11980 KB	Output is correct
12	Correct	7 ms	12056 KB	Output is correct
13	Correct	8 ms	11936 KB	Output is correct
14	Correct	7 ms	11980 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	8 ms	11980 KB	Output is correct
17	Correct	9 ms	11980 KB	Output is correct
18	Correct	7 ms	12052 KB	Output is correct
19	Correct	7 ms	12052 KB	Output is correct
20	Correct	7 ms	11980 KB	Output is correct
21	Correct	7 ms	11980 KB	Output is correct
22	Correct	8 ms	12108 KB	Output is correct
23	Correct	7 ms	11980 KB	Output is correct
24	Correct	7 ms	11960 KB	Output is correct
25	Correct	7 ms	11980 KB	Output is correct
26	Correct	7 ms	11980 KB	Output is correct
27	Correct	7 ms	11980 KB	Output is correct
28	Correct	7 ms	11980 KB	Output is correct
29	Correct	10 ms	11996 KB	Output is correct

Subtask #3
28.0 / 28.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	11980 KB	Output is correct
2	Correct	6 ms	12060 KB	Output is correct
3	Correct	6 ms	11980 KB	Output is correct
4	Correct	8 ms	11980 KB	Output is correct
5	Correct	6 ms	11980 KB	Output is correct
6	Correct	7 ms	11980 KB	Output is correct
7	Correct	7 ms	11980 KB	Output is correct
8	Correct	7 ms	11980 KB	Output is correct
9	Correct	9 ms	11936 KB	Output is correct
10	Correct	7 ms	11980 KB	Output is correct
11	Correct	7 ms	11980 KB	Output is correct
12	Correct	7 ms	12056 KB	Output is correct
13	Correct	8 ms	11936 KB	Output is correct
14	Correct	7 ms	11980 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	8 ms	11980 KB	Output is correct
17	Correct	9 ms	11980 KB	Output is correct
18	Correct	7 ms	12052 KB	Output is correct
19	Correct	7 ms	12052 KB	Output is correct
20	Correct	7 ms	11980 KB	Output is correct
21	Correct	7 ms	11980 KB	Output is correct
22	Correct	8 ms	12108 KB	Output is correct
23	Correct	7 ms	11980 KB	Output is correct
24	Correct	7 ms	11960 KB	Output is correct
25	Correct	7 ms	11980 KB	Output is correct
26	Correct	7 ms	11980 KB	Output is correct
27	Correct	7 ms	11980 KB	Output is correct
28	Correct	7 ms	11980 KB	Output is correct
29	Correct	10 ms	11996 KB	Output is correct
30	Correct	212 ms	30536 KB	Output is correct
31	Correct	224 ms	30400 KB	Output is correct
32	Correct	137 ms	30408 KB	Output is correct
33	Correct	159 ms	30400 KB	Output is correct
34	Correct	147 ms	30404 KB	Output is correct
35	Correct	149 ms	30412 KB	Output is correct
36	Correct	166 ms	30404 KB	Output is correct
37	Correct	147 ms	30404 KB	Output is correct
38	Correct	139 ms	30400 KB	Output is correct
39	Correct	141 ms	30400 KB	Output is correct
40	Correct	144 ms	30404 KB	Output is correct
41	Correct	170 ms	30660 KB	Output is correct
42	Correct	155 ms	30496 KB	Output is correct
43	Correct	139 ms	30408 KB	Output is correct

Subtask #4
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	7 ms	11980 KB	3rd lines differ - on the 1st token, expected: '3304', found: '3586'
2	Halted	0 ms	0 KB	-

Subtask #5
0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	11980 KB	Output is correct
2	Correct	6 ms	12060 KB	Output is correct
3	Correct	6 ms	11980 KB	Output is correct
4	Correct	8 ms	11980 KB	Output is correct
5	Correct	6 ms	11980 KB	Output is correct
6	Correct	7 ms	11980 KB	Output is correct
7	Correct	7 ms	11980 KB	Output is correct
8	Correct	7 ms	11980 KB	Output is correct
9	Correct	9 ms	11936 KB	Output is correct
10	Correct	7 ms	11980 KB	Output is correct
11	Correct	7 ms	11980 KB	Output is correct
12	Correct	7 ms	12056 KB	Output is correct
13	Correct	8 ms	11936 KB	Output is correct
14	Correct	7 ms	11980 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	8 ms	11980 KB	Output is correct
17	Correct	9 ms	11980 KB	Output is correct
18	Correct	7 ms	12052 KB	Output is correct
19	Correct	7 ms	12052 KB	Output is correct
20	Correct	7 ms	11980 KB	Output is correct
21	Correct	7 ms	11980 KB	Output is correct
22	Correct	8 ms	12108 KB	Output is correct
23	Correct	7 ms	11980 KB	Output is correct
24	Correct	7 ms	11960 KB	Output is correct
25	Correct	7 ms	11980 KB	Output is correct
26	Correct	7 ms	11980 KB	Output is correct
27	Correct	7 ms	11980 KB	Output is correct
28	Correct	7 ms	11980 KB	Output is correct
29	Correct	10 ms	11996 KB	Output is correct
30	Correct	212 ms	30536 KB	Output is correct
31	Correct	224 ms	30400 KB	Output is correct
32	Correct	137 ms	30408 KB	Output is correct
33	Correct	159 ms	30400 KB	Output is correct
34	Correct	147 ms	30404 KB	Output is correct
35	Correct	149 ms	30412 KB	Output is correct
36	Correct	166 ms	30404 KB	Output is correct
37	Correct	147 ms	30404 KB	Output is correct
38	Correct	139 ms	30400 KB	Output is correct
39	Correct	141 ms	30400 KB	Output is correct
40	Correct	144 ms	30404 KB	Output is correct
41	Correct	170 ms	30660 KB	Output is correct
42	Correct	155 ms	30496 KB	Output is correct
43	Correct	139 ms	30408 KB	Output is correct
44	Incorrect	7 ms	11980 KB	3rd lines differ - on the 1st token, expected: '3304', found: '3586'
45	Halted	0 ms	0 KB	-

Submission #464883

Compilation message

Subtask #1 12.0 / 12.0

Subtask #2 10.0 / 10.0

Subtask #3 28.0 / 28.0

Subtask #4 0 / 20.0

Subtask #5 0 / 30.0

Subtask #1
12.0 / 12.0

Subtask #2
10.0 / 10.0

Subtask #3
28.0 / 28.0

Subtask #4
0 / 20.0

Subtask #5
0 / 30.0