Submission #369241

#	Time	Username	Problem	Language	Result	Execution time	Memory
369241		vm152	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	633 ms	123900 KiB

tracks

#include <bits/stdc++.h>
using namespace std ;

#define ios ios_base::sync_with_stdio(0); cin.tie(0) ; cout.tie(0)
#define eb emplace_back
#define mp make_pair
#define f first
#define s second
#define endl '\n'

typedef long long int ll ;
typedef long double lb ;
typedef unsigned long long int ul ;
const ll MOD = 1e9 + 7 ;

int dx[4] = {-1, 1, 0, 0}, dy[4] = {0, 0, -1, 1} ;

void solve(){
	 int h, w ;
	 cin >> h >> w ;
	 string s[h] ;
	 for (int i = 0; i < h; i++) cin >> s[i] ;
	 deque<pair<int, int>> q ;
	 int dist[h][w] ;
	 for (int i = 0; i < h; i++) for (int j = 0; j < w; j++) dist[i][j] = 0 ;
	 int ans = 0 ;
	 q.push_back({0, 0}) ;
	 dist[0][0] = 1 ;
	 while (!q.empty()) {
	 	 pair<int, int> c = q.front() ;
	 	 q.pop_front() ;
	 	 ans = max(ans, dist[c.f][c.s]) ;
	 	 for (int i = 0; i < 4; i++) {
			 int x = c.f + dx[i]; int y = c.s + dy[i] ;
			 if (x < 0 || x >= h || y < 0 || y >= w || s[x][y] == '.') continue ;
			 if (dist[x][y] == 0) {
			 	 if (s[x][y] == s[c.f][c.s]) {
			 	 	 dist[x][y] = dist[c.f][c.s] ;
				 	 q.push_front({x, y}) ;
				 }
				 else {
				 	 dist[x][y] = dist[c.f][c.s] + 1 ;
				 	 q.push_back({x, y}) ;
				 }
			 }
		 }
	 }
	 cout << ans << endl ;
}

int main(){
	 ios ;
	 solve() ;
}

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