Submission #810671

#	Time	Username	Problem	Language	Result	Execution time	Memory
810671		serifefedartar	Tracks in the Snow (BOI13_tracks)	C++17	31.25 / 100	2151 ms	1048576 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
typedef long long ll;
#define f first
#define s second
#define MOD 1000000007
#define LOGN 20
#define MAXN 1000005

const int delRow[] = {-1, 0, 0, 1};
const int delCol[] = {0, -1, 1, 0};
vector<vector<int>> grid;
int main() {
    fast
    int H, W;
    cin >> H >> W;

    grid = vector<vector<int>>(H+1, vector<int>(W+1));
    for (int i = 1; i <= H; i++) {
        string s;
        cin >> s;
        for (int j = 1; j <= W; j++) {
            if (s[j-1] == '.')
                grid[i][j] = -1;
            else if (s[j-1] == 'F')
                grid[i][j] = 0;
            else
                grid[i][j] = 1;
        }
    }

    vector<vector<int>> vis(H+1, vector<int>(W+1, false));
    queue<pair<int,int>> q, new_q;
    q.push({1,1});
    int cnt = 1;
    while (!q.empty()) {
        int row = q.front().f;
        int col = q.front().s;
        q.pop();

        vis[row][col] = true;
        for (int i = 0; i < 4; i++) {
            int nRow = delRow[i] + row;
            int nCol = delCol[i] + col;
            if (nRow >= 1 && nCol >= 1 && nRow <= H && nCol <= W && !vis[nRow][nCol] && grid[nRow][nCol] != -1) {
                if (grid[nRow][nCol] == grid[row][col])
                    q.push({nRow, nCol});
                else
                    new_q.push({nRow, nCol});
            }
        }

        if (q.empty() && !new_q.empty()) {
            q = new_q;
            cnt++;
            new_q = queue<pair<int,int>>();
        }
    }
    cout << cnt << "\n";
}

• Subtask 1: 5 / 30
• Subtask 2: 26.25 / 70