Submission #860625

#	Time	Username	Problem	Language	Result	Execution time	Memory
860625		serifefedartar	Patkice II (COCI21_patkice2)	C++17	15 / 110	711 ms	524288 KiB

Main

#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 7;
const ll LOGN = 18; 
const ll MAXN = 1e5 + 100;

vector<pair<int,pair<int,int>>> graph[2005][2005], rev[2005][2005];
int dist[2005][2005];
vector<string> grid;
pair<int,int> s, e;
void change(int row, int col, int nrow, int ncol) {
	if (nrow > row)
		grid[row][col] = 'v';
	else if (nrow < row)
		grid[row][col] = '^';
	else if (ncol < col)
		grid[row][col] = '<';
	else
		grid[row][col] = '>'; 
}

void dfs(int row, int col, int old_row, int old_col, int target) {
	for (auto u : rev[row][col]) {
		int w = u.f;
		int nrow = u.s.f;
		int ncol = u.s.s;
		if (nrow == old_row && ncol == old_col)
			continue;
		if (dist[nrow][ncol] + w == target) {
			change(nrow, ncol, row, col);
			dfs(nrow, ncol, row, col, target - w);
			return ;
		}
	}
}

int r, c;
bool check(int row, int col) {
	if (row >= 0 && col >= 0 && r > row && c > col)
		return true;
	return false;
}

int main() {
	fast
	cin >> r >> c;

	for (int i = 0; i < 2005; i++) {
		for (int j = 0; j < 2005; j++)
			dist[i][j] = 1e8;
	}

	grid = vector<string>(r);
	for (int i = 0; i < r; i++)
		cin >> grid[i];

	for (int i = 0; i < r; i++) {
		for (int j = 0; j < c; j++) {
			if (grid[i][j] == '>') {
			    if (check(i, j+1))
				    graph[i][j].push_back({0, {i, j+1}});
				if (check(i+1, j))
				    graph[i][j].push_back({1, {i+1, j}});
				if (check(i, j-1))
				    graph[i][j].push_back({1, {i, j-1}});
				if (check(i-1, j))
					graph[i][j].push_back({1, {i-1, j}});
			} else if (grid[i][j] == '<') {
				if (check(i, j+1))
					graph[i][j].push_back({1, {i, j+1}});
				if (check(i+1, j))
					graph[i][j].push_back({1, {i+1, j}});
				if (check(i, j-1))
					graph[i][j].push_back({0, {i, j-1}});
				if (check(i-1, j))
					graph[i][j].push_back({1, {i-1, j}});
			} else if (grid[i][j] == 'v') {
				if (check(i, j+1))
					graph[i][j].push_back({1, {i, j+1}});
				if (check(i+1, j))
					graph[i][j].push_back({0, {i+1, j}});
				if (check(i, j-1))
					graph[i][j].push_back({1, {i, j-1}});
				if (check(i-1, j))
					graph[i][j].push_back({1, {i-1, j}});
			} else if (grid[i][j] == '^') {
				if (check(i, j+1))
					graph[i][j].push_back({1, {i, j+1}});
				if (check(i+1, j))
					graph[i][j].push_back({1, {i+1, j}});
				if (check(i, j-1))
					graph[i][j].push_back({1, {i, j-1}});
				if (check(i-1, j))
					graph[i][j].push_back({0, {i-1, j}});
			} else if (grid[i][j] == '.') {
				if (check(i, j+1))
					graph[i][j].push_back({1, {i, j+1}});
				if (check(i+1, j))
					graph[i][j].push_back({1, {i+1, j}});
				if (check(i, j-1))
					graph[i][j].push_back({1, {i, j-1}});
				if (check(i-1, j))
					graph[i][j].push_back({1, {i-1, j}});
			} else if (grid[i][j] == 'o') {
				s = {i, j};
				if (check(i, j+1))
					graph[i][j].push_back({0, {i, j+1}});
				if (check(i+1, j))
					graph[i][j].push_back({0, {i+1, j}});
				if (check(i, j-1))
					graph[i][j].push_back({0, {i, j-1}});
				if (check(i-1, j))
					graph[i][j].push_back({0, {i-1, j}});
			} else
				e = {i, j};
		} 
	}

	deque<pair<int,int>> dq;
	dq.push_back(s);
	dist[s.f][s.s] = 0;
	while (!dq.empty()) {
		int row = dq.front().f;
		int col = dq.front().s;
		dq.pop_front();

		for (auto u : graph[row][col]) {
			int w = u.f;
			int nrow = u.s.f;
			int ncol = u.s.s;
			if (dist[nrow][ncol] > w + dist[row][col]) {
				dist[nrow][ncol] = w + dist[row][col];
				if (w == 1)
					dq.push_back({nrow, ncol});
				else
					dq.push_front({nrow, ncol});
			}
		}
	}

	cout << dist[e.f][e.s] << "\n";

	for (int i = 0; i < 2005; i++) {
		for (int j = 0; j < 2005; j++) {
			while (graph[i][j].size()) {
				pair<int,pair<int,int>> here = graph[i][j].back();
				graph[i][j].pop_back();
				rev[here.s.f][here.s.s].push_back({here.f, {here.s.f, here.s.s}});
			}
		}
	}

	dfs(e.f, e.s, e.f, e.s, dist[e.f][e.s]);
	grid[s.f][s.s] = 'o';
	for (int i = 0; i < r; i++) 
		cout << grid[i] << "\n";
}

• Subtask 1: 15 / 30
• Subtask 2: 0 / 80