1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
| #include <iostream>
#include <cstring>
#include <queue>
#include <algorithm>
using namespace std;
int map[100][100];
bool visited[100][100];
int N, ans =1e9;
int dx[4] = { -1, 1, 0, 0 };
int dy[4] = { 0, 0, -1, 1 };
void DFS(int x, int y, int idx) {
visited[x][y] = true;
map[x][y] = idx;
for (int dir = 0; dir < 4; ++dir) {
int d_x = x + dx[dir];
int d_y = y + dy[dir];
if (d_x > -1 && d_y > -1 && d_x < N && d_y < N) {
if (map[d_x][d_y] == 0 || visited[d_x][d_y]) continue;
DFS(d_x, d_y, idx);
}
}
}
int BFS(int x, int y) {
memset(visited, false, sizeof(visited));
queue<pair<int, int>> q;
q.push({ x, y });
int temp = map[x][y];
int res = 0;
while (int len = q.size()) {
while(len--) {
int x = q.front().first;
int y = q.front().second;
q.pop();
for (int dir = 0; dir < 4; ++dir) {
int d_x = x + dx[dir];
int d_y = y + dy[dir];
if (d_x > -1 && d_y > -1 && d_x < N && d_y < N) {
if (map[d_x][d_y] != 0 && map[d_x][d_y] != temp) return res;
if (map[d_x][d_y] == 0 && !visited[d_x][d_y]) {
visited[d_x][d_y] = true;
q.push({ d_x, d_y });
}
}
}
}
res++;
}
return ans;
}
int main() {
cin >> N; int idx = 1;
for (int i = 0; i < N; ++i) {
for (int j = 0; j < N; ++j) {
cin >> map[i][j];
}
}
for (int i = 0; i < N; ++i) {
for (int j = 0; j < N; ++j) {
if (visited[i][j] || map[i][j] == 0) continue;
DFS(i, j, idx++);
}
}
for (int i = 0; i < N; ++i) {
for (int j = 0; j < N; ++j) {
if (map[i][j] == 0) continue;
ans = min(ans, BFS(i, j));
}
}
cout << ans << "\n";
return 0;
}
|
