Submission #504916

#	Time	Username	Problem	Language	Result	Execution time	Memory
504916		shubham20_03	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	557 ms	235976 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
#define deb(x) cout<<#x<<'='<<x<<'\n';
#define deb2(x,y) cout<<#x<<'='<<x<<", "<<#y<<'='<<y<<'\n';
#define int long long
#define all(x) (x).begin(), (x).end()
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second
#define sz(x) (int)(x).size()
const long double PI = acos(-1);
const int mod = 1e9 + 7, inf = 1e10;
const int D = 4010;

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};

int n, m;
string a[D];
int d[D][D];

void solve_test() {
    cin >> n >> m;
    for (int i = 0; i < n; i++)
        cin >> a[i];

    deque<pii> q;
    q.pb({0, 0});
    d[0][0] = 1;

    int ans = 1;
    while (!q.empty()) {
        pii u = q.front();
        int ux = u.f, uy = u.s;
        q.pop_front();

        ans = max(ans, d[ux][uy]);

        for (int i = 0; i < 4; i++) {
            int vx = ux + dx[i];
            int vy = uy + dy[i];

            if (vx<0 or vx >= n or vy<0 or vy >= m)
                continue;

            if (a[vx][vy] == '.')
                continue;

            int wt = (a[ux][uy] != a[vx][vy]);
            if (d[vx][vy] == 0) {
                d[vx][vy] = d[ux][uy] + wt;
                if (wt) q.pb({vx, vy});
                else q.push_front({vx, vy});
            }
        }
    }

    cout << ans << '\n';
}

signed main() {
    fastio

    solve_test();

    return 0;
}

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