CF877
bfs
1 #include <bits/stdc++.h> 2 using namespace std; 3 const int maxn =1010; 4 5 char mp[maxn][maxn]; 6 int vis[maxn][maxn], dis[maxn][maxn]; 7 8 struct Node{ 9 int x, y; 10 Node(int x = 0, int y = 0) : x(x), y(y) {} 11 }; 12 13 int d[4][2] = {0, 1, 0, -1, 1, 0, -1, 0}; 14 int sx, sy, ex, ey; 15 int n, m, k; 16 17 void bfs(){ 18 Node p1, p2; 19 queue<Node> q; 20 q.push(Node(sx, sy)); 21 vis[sx][sy] = (1<<4) - 1; 22 dis[sx][sy] = 0; 23 while(!q.empty()){ 24 p2 = q.front(); 25 q.pop(); 26 if(p2.x == ex && p2.y == ey) return ; 27 for(int i = 0; i < 4; i++){ 28 for(int j = 1; j <= k; j++){ 29 int dx = p2.x + d[i][0] * j; 30 int dy = p2.y + d[i][1] * j; 31 if(dx < 0 || dx >= n || dy < 0 || dy >= m || mp[dx][dy] == '#') break; 32 if(vis[dx][dy] & (1<<i)) break; 33 int ok = 0; 34 if(!vis[dx][dy]) ok = 1; 35 vis[dx][dy] |= (1<<i); 36 if(ok){ 37 dis[dx][dy] = dis[p2.x][p2.y] + 1; 38 q.push(Node(dx, dy)); 39 } 40 41 } 42 43 } 44 } 45 46 } 47 48 int main(){ 49 //freopen("in.txt", "r", stdin); 50 memset(dis, -1, sizeof(dis)); 51 memset(vis, 0, sizeof(vis)); 52 scanf("%d %d %d", &n, &m, &k); 53 for(int i = 0; i < n; i++) scanf("%s", mp[i]); 54 scanf("%d %d %d %d", &sx, &sy, &ex, &ey); 55 sx--; sy--; ex--; ey--; 56 bfs(); 57 printf("%d ", dis[ex][ey]); 58 }