Submission #366953

#	Time	Username	Problem	Language	Result	Execution time	Memory
366953		vishesh312	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	1148 ms	984844 KiB

tracks

#include "bits/stdc++.h"
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using ordered_set = tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>;
*/

#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()

using ll = long long;
const int mod = 1e9+7;
vector<string> v;
int n, m;
int ans = 0;
array<vector<array<int, 2>>, 2> cur;

bool isValid(int i, int j) {
    return i < n and i >= 0 and j < m and j >= 0 and v[i][j] != '.';
}

vector<array<int, 2>> moves = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};

void dfs(array<int, 2> a) {
    char c = v[a[0]][a[1]];
    v[a[0]][a[1]] = '.';
    for (auto m : moves) {
        int nx = a[0] + m[0], ny = a[1] + m[1];
        if (isValid(nx, ny)) {
            if (v[nx][ny] == c) {
                dfs({nx, ny});
            } else {
                cur[ans&1?0:1].push_back({nx, ny});
            }
        }
    }
}

void solve(int tc) {
    cin >> n >> m;
    v.resize(n);
    for (auto &x : v) cin >> x;
    cur[0].push_back({0, 0});
    while (!cur[ans&1].empty()) {
        for (auto x : cur[ans&1]) {
            if (isValid(x[0], x[1])) {
                dfs(x);
            }
        }
        cur[ans&1].clear();
        ++ans;
    }
    cout << ans << '\n';
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    int tc = 1;
    //cin >> tc;
    for (int i = 1; i <= tc; ++i) solve(i);
    return 0;
}

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