Submission #992099

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
992099	2024-06-03T22:51:08 Z	vjudge1	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	1108 ms	192392 KB

tracks

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

#define ff first
#define ss second
#define pb push_back

typedef long long ll;
typedef pair<int,int> pii;



const int S = 4000;
char meadow[S][S];
int dist[S][S];
bool vis[S][S];
const int INF = 1e8;

void reset(){
	for(int i = 0; i < S; i++){
		for(int j = 0; j < S; j++){
			dist[i][j] = INF;
		}
	}
}
int solve(int h, int w){

	reset();
	int ans = 0;
	pii start = {0,0};
	deque<pii> dq;
	dq.push_back(start);
	dist[0][0] = 0;
	while(dq.size()){
		auto [a, b] = dq.front(); dq.pop_front();
		
		if(vis[a][b]) continue;
		vis[a][b] = true;
		char animal = meadow[a][b];
		// obtener vecinos
		vector<pii> vecinos;
		if (a > 0){
			if(!vis[a-1][b]){
				pii up = {a-1, b};
				char animal_up = meadow[up.ff][up.ss];
				if(animal_up != '.'){
					vecinos.pb(up);
				}
			}
		}
		if(a < h-1){
			if(!vis[a+1][b]){
				pii down = {a+1, b};
				char animal_down = meadow[down.ff][down.ss];
				if(animal_down != '.'){
					vecinos.pb(down);
				}
			}			
		}
		if(b > 0){
			if(!vis[a][b-1]){
				pii left = {a, b-1};
				char animal_left = meadow[left.ff][left.ss];
				if(animal_left != '.'){
					vecinos.pb(left);
				}
			}			
		}
		if(b < w-1){
			if(!vis[a][b+1]){
				pii right = {a, b+1};
				char animal_right = meadow[right.ff][right.ss];
				if(animal_right != '.'){
					vecinos.pb(right);
				}
			}
		}
		
		// iterar por vecinos
		for(auto [x,y]: vecinos){
			int d = 0;
			if(meadow[x][y] != animal){
				d = 1;
			}
			// if (dist[curr_node] + d > dist[to]) continue;
			if(dist[a][b] + d > dist[x][y]) continue;
			
			dist[x][y] = dist[a][b] + d;
			
			ans = max(ans, dist[x][y]);
			
			if(d == 1){
				dq.push_back({x,y});
			}
			else if(d == 0){
				dq.push_front({x,y});
			}
		}
		
	}
	return ans;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  
  int h, w; cin >> h >> w;
  
  for(int i = 0; i < h; i++){
	  for(int j = 0; j < w; j++){
		  char x; cin >> x;
		  meadow[i][j] = x;
	  }
  }
  cout << solve(h,w)+1;
  
  
	  
  
}

Subtask #1

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	34 ms	67932 KB	Output is correct
2	Correct	15 ms	66140 KB	Output is correct
3	Correct	15 ms	66140 KB	Output is correct
4	Correct	25 ms	68188 KB	Output is correct
5	Correct	18 ms	67164 KB	Output is correct
6	Correct	15 ms	66140 KB	Output is correct
7	Correct	19 ms	66140 KB	Output is correct
8	Correct	16 ms	66136 KB	Output is correct
9	Correct	15 ms	66392 KB	Output is correct
10	Correct	17 ms	66904 KB	Output is correct
11	Correct	17 ms	66816 KB	Output is correct
12	Correct	20 ms	67164 KB	Output is correct
13	Correct	16 ms	67164 KB	Output is correct
14	Correct	17 ms	67160 KB	Output is correct
15	Correct	30 ms	70128 KB	Output is correct
16	Correct	34 ms	67932 KB	Output is correct
17	Correct	26 ms	67928 KB	Output is correct
18	Correct	31 ms	68184 KB	Output is correct

Subtask #2

70.0 / 70.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	26 ms	93448 KB	Output is correct
2	Correct	73 ms	75088 KB	Output is correct
3	Correct	308 ms	94288 KB	Output is correct
4	Correct	89 ms	79564 KB	Output is correct
5	Correct	216 ms	87892 KB	Output is correct
6	Correct	1043 ms	119244 KB	Output is correct
7	Correct	23 ms	94296 KB	Output is correct
8	Correct	24 ms	93524 KB	Output is correct
9	Correct	16 ms	66112 KB	Output is correct
10	Correct	14 ms	66140 KB	Output is correct
11	Correct	23 ms	94040 KB	Output is correct
12	Correct	16 ms	66652 KB	Output is correct
13	Correct	69 ms	75100 KB	Output is correct
14	Correct	48 ms	71644 KB	Output is correct
15	Correct	32 ms	72028 KB	Output is correct
16	Correct	43 ms	67604 KB	Output is correct
17	Correct	150 ms	79956 KB	Output is correct
18	Correct	84 ms	80080 KB	Output is correct
19	Correct	96 ms	79440 KB	Output is correct
20	Correct	88 ms	79016 KB	Output is correct
21	Correct	202 ms	88404 KB	Output is correct
22	Correct	212 ms	87888 KB	Output is correct
23	Correct	279 ms	84048 KB	Output is correct
24	Correct	187 ms	90616 KB	Output is correct
25	Correct	306 ms	94288 KB	Output is correct
26	Correct	701 ms	192392 KB	Output is correct
27	Correct	984 ms	120460 KB	Output is correct
28	Correct	1058 ms	119108 KB	Output is correct
29	Correct	1108 ms	115408 KB	Output is correct
30	Correct	959 ms	123480 KB	Output is correct
31	Correct	783 ms	91728 KB	Output is correct
32	Correct	779 ms	124612 KB	Output is correct