猫和老鼠 蓝桥杯／手速／暴力练习赛（暴力搜索）

  1 /*
  2     思路：如果猫和老鼠不相遇，那么一定是猫在某一个格子沿着某一个方向重复走了2次以上并且
  3     老鼠也是这样。 
  4 */ 
  5 #include<iostream> 
  6 #include<cstring> 
  7 #include<cstdio> 
  8 #include<algorithm>
  9 using namespace std;
 10 
 11 char mp[15][15];
 12 
 13 const int left_dir = 1;
 14 const int right_dir = 2;
 15 const int up = 3;
 16 const int down = 4;
 17 const int mouse = 1;
 18 const int cat = 0;
 19 
 20 struct node{
 21     int x, y;
 22     int dir;
 23     node(){
 24         dir = up;
 25     }
 26     
 27     bool flag[15][15][5];//记录当前格子在某一个方向上是否走过 
 28     
 29     void init(int x, int y){
 30         memset(flag, false, sizeof(flag));
 31         this->x = x;
 32         this->y = y;
 33         flag[x][y][up] = true;
 34     }
 35 };
 36 
 37 node nd[2];
 38 int cnt = 0;
 39 
 40 bool move(int i){
 41     int x=nd[i].x, y=nd[i].y;
 42     int newdir;
 43     switch(nd[i].dir){
 44         case up:
 45             x-=1;
 46             newdir = right_dir;
 47             break;
 48         case down:
 49             x+=1;
 50             newdir = left_dir;
 51             break;
 52         case left_dir:
 53             y-=1;
 54             newdir = up;
 55             break;
 56         case right_dir:
 57             y+=1;
 58             newdir = down;
 59             break;
 60     }
 61     if(mp[x][y] != '*'){
 62         nd[i].x = x;
 63         nd[i].y = y;
 64     } else {
 65         nd[i].dir = newdir;
 66     }
 67     
 68     if(!nd[i].flag[x][y][nd[i].dir]){
 69         nd[i].flag[x][y][nd[i].dir] = true;
 70         return true;        
 71     } else return false;
 72 }
 73 
 74 void test(){
 75     bool flag = true, flag1=false, flag2=false;
 76     while(flag){
 77         if(nd[cat].x == nd[mouse].x && nd[cat].y == nd[mouse].y) break;
 78         if(!move(cat))
 79             flag1 = true;
 80         if(!move(mouse))
 81             flag2 = true;
 82         ++cnt;
 83         if(flag1 && flag2) flag = false;
 84     }
 85     if(flag) printf("%d\n", cnt);
 86     else printf("-1\n");
 87 }
 88 
 89 int main() {
 90     memset(mp, '*', sizeof(mp));
 91     for(int i=1; i<=10; ++i){
 92         scanf("%s", mp[i]+1);
 93         mp[i][strlen(mp[i]+1)+1] = '*';
 94         for(int j=1; j<=10; ++j){
 95             if(mp[i][j]=='C'){
 96                 nd[cat].init(i, j);
 97                 mp[i][j] = '.';
 98             }
 99             else if(mp[i][j] == 'M'){
100                 nd[mouse].init(i, j);
101                 mp[i][j] = '.';
102             }
103         }
104         getchar();
105     }
106     test();
107     return 0;
108 }
109 /*
110 *...*.....
111 ......*...
112 ...*...*..
113 ..........
114 ...*.C....
115 *.....*...
116 ...*......
117 ..M......*
118 ...*.*....
119 .*.*......
120 */