Submission #1161025

#	Time	Username	Problem	Language	Result	Execution time	Memory
1161025		Nonoze	Tracks in the Snow (BOI13_tracks)	C++20	31.77 / 100	2100 ms	144804 KiB

tracks

/*
*	Author: Nonoze
*	Created: Monday 03/03/2025
*/
#include <bits/stdc++.h>
using namespace std;

#ifndef IN_LOCAL
	#define dbg(...)
#endif

// #define cout cerr << "OUT: "
#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) return (void)(cout << x << endl)

template<typename T> void read(T& x) { cin >> x;}
template<typename T1, typename T2> void read(pair<T1, T2>& p) { read(p.first), read(p.second);}
template<typename T> void read(vector<T>& v) { for (auto& x : v) read(x); }
template<typename T1, typename T2> void read(T1& x, T2& y) { read(x), read(y); }
template<typename T1, typename T2, typename T3> void read(T1& x, T2& y, T3& z) { read(x), read(y), read(z); }
template<typename T1, typename T2, typename T3, typename T4> void read(T1& x, T2& y, T3& z, T4& zz) { read(x), read(y), read(z), read(zz); }
template<typename T> void print(vector<T>& v) { for (auto& x : v) cout << x << ' '; cout << endl; }

#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define make_unique(v) sort(all(v)), v.erase(unique(all(v)), (v).end())
#define pb push_back
#define mp(a, b) make_pair(a, b)
#define fi first
#define se second
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
#define YES cout << "YES" << endl
#define NO cout << "NO" << endl
#define QYES quit("YES")
#define QNO quit("NO")

#define int long long
#define double long double
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=20;



void solve();

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;
	// cin >> tt;
	while(tt--) solve();
	return 0;
}


vector<pair<int, int>> pos={{1, 0}, {0, 1}, {-1, 0}, {0, -1}};

int n, k, m;
vector<string> a;


void solve() {
	read(n, m);
	a.clear(), a.resize(n); read(a);
	vector<vector<int>> dist(n, vector<int>(m, inf));
	queue<pair<int, int>> q; q.push({0, 0}); dist[0][0]=1;
	int ans=0;
	while (!q.empty()) {
		auto [x, y]=q.front(); q.pop();
		cmax(ans, dist[x][y]);
		for (auto [u, v]: pos) {
			int nx=x+u, ny=y+v;
			if (nx>=0 && nx<n && ny>=0 && ny<m && a[nx][ny]!='.' && dist[nx][ny]>dist[x][y]+(a[nx][ny]!=a[x][y])) {
				dist[nx][ny]=dist[x][y]+(a[nx][ny]!=a[x][y]);
				q.push({nx, ny});
			}
		}
	}
	cout << ans << endl;
}

• Subtask 1: 3.3333 / 30
• Subtask 2: 28.4375 / 70