P1141 01迷宫 （记忆化搜索）

 1 #include <math.h>
 2 #include <stdio.h>
 3 #include <stdlib.h>
 4 #include <iostream>
 5 #include <algorithm>
 6 #include <string>
 7 #include <string.h>
 8 #include <vector>
 9 #include <map>
10 #include <stack>
11 #include <set>
12 #include <queue>
13 
14 
15 #define LL long long
16 #define INF 0x3f3f3f3f
17 #define ls nod<<1
18 #define rs (nod<<1)+1
19 const int maxn = 4e5+10;
20 const double eps = 1e-9;
21 
22 int n,m,cnt;
23 int a[1010][1010],res[1010][1010];
24 int dik[1000010][2];
25 int dir[4][2] = {{-1,0},{1,0},{0,-1},{0,1}};
26 
27 void dfs(int row,int col) {
28     cnt++;
29     dik[cnt][0] = row;
30     dik[cnt][1] = col;
31     res[row][col] = 1;
32     for (int i=0;i<4;i++) {
33         int new_row = row + dir[i][0];
34         int new_col = col + dir[i][1];
35         if (new_row<1 || new_col<1 || new_row>n || new_col>n || res[new_row][new_col]) {
36             continue;
37         }
38         if (a[new_row][new_col] == a[row][col]) {
39             continue;
40         }
41         dfs(new_row,new_col);
42     }
43 }
44 
45 int main() {
46     scanf("%d%d",&n,&m);
47     for (int i=1;i<=n;i++) {
48         for (int j=1;j<=n;j++) {
49             scanf("%1d",&a[i][j]);
50         }
51     }
52     for (int i=1;i<=m;i++) {
53         cnt = 0;
54         int row,col;
55         scanf("%d%d",&row,&col);
56         if (res[row][col] > 0) {
57             printf("%d\n",res[row][col]);
58             continue;
59         }
60         dfs(row,col);
61         for (int j=1;j<=cnt;j++) {
62             res[dik[j][0]][dik[j][1]] = cnt;
63         }
64         printf("%d\n",cnt);
65     }
66     return 0;
67 }