Submission #598243

#	Time	Username	Problem	Language	Result	Execution time	Memory
598243		yanndev	Ancient Books (IOI17_books)	C++17	0 / 100	2084 ms	223992 KiB

books

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

const int NOT_VIS = 0;
const int CUR_VIS = 1;
const int VIS = 2;
map<pair<vector<int>, pair<int, int>>, pair<int, ll>> vis {};

inline ll recSolve(int pos, vector<int> vals, int carry) {
    // move out of bounds
	if (pos >= (int)vals.size() || pos < 0)
		return 1e9;
    // don't allow to cycle
	if (vis[{vals, {pos, carry}}].first == CUR_VIS)
		return 1e9;
    // if already visited, return answer
	if (vis[{vals, {pos, carry}}].first == VIS)
		return vis[{vals, {pos, carry}}].second;

	ll mnAns = 1e9;

	bool ok = true;
	for (int i = 0; i < (int)vals.size(); i++)
		if (vals[i] != i)
			ok = false;

    // if we have correct tables
	if (ok) {
		//printf("food bruh %d %d\n", pos);
		vis[{vals, {pos, carry}}] = {VIS, pos};
		return pos;
	}

    // mark as visiting
	vis[{vals, {pos, carry}}] = {CUR_VIS, 1e9};

    // jump to the right
	mnAns = min(mnAns, 1 + recSolve(pos + 1, vals, carry));
    // jump to the left
	mnAns = min(mnAns, 1 + recSolve(pos - 1, vals, carry));

    // change carried book
	swap(carry, vals[pos]);
	mnAns = min(mnAns, recSolve(pos, vals, carry));
	swap(carry, vals[pos]);
	vis[{vals, {pos, carry}}] = {VIS, mnAns};
	return mnAns;
}

ll minimum_walk(vector<int> p, int s) {
    int n = (int)p.size();
	return recSolve(0, p, -1);
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:52:9: warning: unused variable 'n' [-Wunused-variable]
   52 |     int n = (int)p.size();
      |         ^

• Subtask 1: 0 / 12
• Subtask 2: 0 / 10
• Subtask 3: 0 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30