Submission #382043

#	Time	Username	Problem	Language	Result	Execution time	Memory
382043		Araragi	Patkice II (COCI21_patkice2)	C++17	0 / 110	1 ms	492 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("00")
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair<int, int> pii;
ll time() {return chrono::system_clock().now().time_since_epoch().count();}
mt19937 rnd(time());
const int inf = 1e9;
const ll inf64 = 1e18;
#define ft first
#define fin(x) ifstream cin("x.in");
#define fout(x) ofstream cout("x.out");
#define sd second
#define pb push_back
#define sz(x) (int)x.size()

char grid[2001][2001];
int dst[2001][2001];
bool was[2001][2001];
array<int, 2> mem[2001][2001];

int steps[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};

void solve()
{
    int n, m;
    cin >> n >> m;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            dst[i][j] = inf;

    int sx = 0, sy = 0, ex = 0, ey = 0;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
        {
            cin >> grid[i][j];
            if (grid[i][j] == 'o')
            {
                sx = i;
                sy = j;
            }
            else if (grid[i][j] == 'x')
            {
                ex = i;
                ey = j;
            }
        }

    queue< pair< pair<int, int>, int > > q;

    q.push({{0, sx}, sy});
    was[sx][sy] = true;
    dst[sx][sy] = 0;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            mem[i][j] = {-1, -1};

    while (!q.empty())
    {
        int cost = -q.front().ft.ft;
        int fx = q.front().ft.sd;
        int fy = q.front().sd;
        q.pop();

        if (cost > dst[fx][fy])
            continue;

        was[fx][fy] = true;
        for (int i = 0; i < 4; i++)
        {
            int cx = fx + steps[i][0];
            int cy = fy + steps[i][1];

            int pay = 1;

            if (fx == sx && fy == sy)
                pay = 0;
            if (steps[i][0] == 1 && grid[fx][fy] == 'v')
                pay = 0;
            if (steps[i][0] == -1 && grid[fx][fy] == '^')
                pay = 0;
            if (steps[i][1] == 1 && grid[fx][fy] == '>')
                pay = 0;
            if (steps[i][1] == -1 && grid[fx][fy] == '<')
                pay = 0;

            if (!(cx >= 0 && cx < n && cy >= 0 && cy < m && !was[cx][cy]))
                continue;

            if (cost + pay < dst[cx][cy])
            {
                dst[cx][cy] = cost + pay;
                q.push({{-(cost + pay), cx}, cy});
                mem[cx][cy] = {fx, fy};
            }
        }
    }

    vector< array<int, 2> > path;
    int x = ex, y = ey;
    while (x != sx || y != sy)
    {
        path.pb({x, y});
        auto nx = mem[x][y];
        x = nx[0];
        y = nx[1];
    }

    //path.pb({sx, sy});

    reverse(path.begin(), path.end());

    //for (auto it : path)
    //    cout << it[0] + 1 << " " << it[1] + 1 << " " << it[2] << '\n';

    int lst = 0;

    for (int i = 0; i < sz(path) - 1; i++)
    {
        //cerr << path[i][0] + 1 << " " << path[i][1] +  1 << '\n';
        //cerr << path[i + 1][0] + 1 << " " << path[i + 1][1] + 1 << '\n';

        if (path[i + 1][0] - path[i][0] == 1)
        {
            grid[path[i][0]][path[i][1]] = 'v';
        }
        else if (path[i][0] - path[i + 1][0] == 1)
        {
            grid[path[i][0]][path[i][1]] = '^';
        }
        else if (path[i + 1][1] - path[i][1] == 1)
        {
            grid[path[i][0]][path[i][1]] = '>';
        }
        else if (path[i][1] - path[i + 1][1] == 1)
        {
            grid[path[i][0]][path[i][1]] = '<';
        }
    }

    cout << dst[ex][ey] << '\n';
    for (int i = 0; i < n; i++, cout << '\n')
        for (int j = 0; j < m; j++)
            cout << grid[i][j];
}

int main()
{
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    #ifdef _LOCAL_
        system("color 2");
    #endif // _LOCAL_

    int t = 1;

    while (t--)
        solve();

}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:121:9: warning: unused variable 'lst' [-Wunused-variable]
  121 |     int lst = 0;
      |         ^~~

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