제출 #1283067

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1283067		ishaanthenerd	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	814 ms	110848 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1e9 + 7;
using pii = pair<int, int>;

bool in_bounds(int x, int y, int r, int c) {
    return x >= 0 && x < r && y >= 0 && y < c;
}

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

    int h, w;
    cin >> h >> w;
    vector<vector<char>> grid(h, vector<char>(w));
    for (int i = 0; i < h; i++) for (int j = 0; j < w; j++) cin >> grid.at(i).at(j);

    vector<vector<int>> ans(h, vector<int>(w, INT_MAX));
    deque<pii> dq;
    dq.push_back({0, 0});
    ans.at(0).at(0) = 1;
    while (!dq.empty()) {
        pii p = dq.front();
        int x = p.first, y = p.second;
        dq.pop_front();
        for (int k = -2; k < 2; k++) {
            int dx = k % 2, dy = (k + 1) % 2;
            if (in_bounds(x + dx, y + dy, h, w)) {
                if (grid.at(x + dx).at(y + dy) == '.') continue;
                int new_dist = ans.at(x).at(y) + (grid.at(x).at(y) != grid.at(x + dx).at(y + dy));
                if (new_dist < ans.at(x + dx).at(y + dy)) {
                    ans.at(x + dx).at(y + dy) = new_dist;
                    if (grid.at(x).at(y) != grid.at(x + dx).at(y + dy)) dq.push_back({x + dx, y + dy});
                    else dq.push_front({x + dx, y + dy});
                }
            }
        }
    }

    int final_ans = 0;
    for (int i = 0; i < h; i++) for (int j = 0; j < w; j++) if (ans.at(i).at(j) != INT_MAX) final_ans = max(final_ans, ans.at(i).at(j));
    cout << final_ans << endl;

    return 0;
}

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