hdu 1026 Ignatius and the Princess I(优先队列+bfs+记录路径)

  1 #include <cstdio>
  2 #include <cstring>
  3 #include <cstring>
  4 #include <cmath>
  5 #include <algorithm>
  6 #include <queue>
  7 using namespace std;
  8 
  9 struct node
 10 {
 11     int x, y, step;
 12     bool operator < (const node& a) const
 13     {
 14         return a.step < step;
 15     }
 16 };
 17 
 18 int go[4][2] = {{1, 0},{-1, 0}, {0, 1}, {0, -1}};
 19 
 20 int n, m, step;
 21 bool v[110][110];
 22 char mp[110][110];
 23 int last[110][110];
 24 
 25 bool bfs()
 26 {
 27     node p, q;
 28     p.x = n-1;
 29     p.y = m-1;
 30     p.step = 0;
 31     if(mp[n-1][m-1] >= ‘0‘ && mp[n-1][m-1] <= ‘9‘) p.step += mp[n-1][m-1] -‘0‘;
 32 
 33     priority_queue <node> que;
 34     if(mp[p.x][p.y] != ‘X‘)
 35     que.push(p);
 36     v[p.x][p.y] = 1;
 37 
 38     while(!que.empty())
 39     {
 40         p = que.top();
 41         que.pop();
 42 
 43         for(int i = 0; i < 4; i++)
 44         {
 45             int x = p.x+go[i][0];
 46             int y = p.y+go[i][1];
 47 
 48             if(x >= 0 && x < n && y >= 0 && y < m && !v[x][y])
 49             {
 50                 if(mp[x][y] == ‘X‘) continue;
 51 
 52                 q.x = x; q.y = y; q.step = p.step+1;
 53                 if(mp[x][y] >= ‘1‘ && mp[x][y] <= ‘9‘) q.step += mp[x][y]-‘0‘;
 54                 que.push(q);
 55                 v[x][y] = 1;
 56                 last[x][y] = p.x*1000+p.y;
 57                 if(x == 0 && y == 0) {step = q.step; return 1;}
 58 
 59             }
 60         }
 61     }
 62     return 0;
 63 }
 64 
 65 void output()
 66 {
 67     printf("It takes %d seconds to reach the target position, let me show you the way.\n", step);
 68     int x = 0;
 69     int y = 0;
 70     int i = 1;
 71     while(x != n-1 || y != m-1)
 72     {
 73         if(mp[x][y] >= ‘1‘ && mp[x][y] <= ‘9‘)
 74         {
 75             int stop = mp[x][y] - ‘0‘;
 76             while(stop--)
 77             {
 78                 printf("%ds:FIGHT AT (%d,%d)\n", i++, x, y);
 79             }
 80         }
 81         printf("%ds:(%d,%d)->(%d,%d)\n", i++, x, y, last[x][y]/1000, last[x][y]%1000);
 82 
 83         int t = last[x][y]/1000;
 84         y = last[x][y]%1000;
 85         x = t;
 86     }
 87     if(mp[x][y] >= ‘1‘ && mp[x][y] <= ‘9‘)
 88     {
 89         int stop = mp[x][y] - ‘0‘;
 90         while(stop--)
 91         {
 92             printf("%ds:FIGHT AT (%d,%d)\n", i++, x, y);
 93         }
 94     }
 95 }
 96 
 97 int main()
 98 {
 99     //freopen("test.txt", "r", stdin);
100     while(~scanf("%d%d", &n, &m))
101     {
102         memset(mp, 0, sizeof(mp));
103         memset(v, 0, sizeof(v));
104         memset(last, 0, sizeof(last));
105         for(int i = 0; i < n; i++)
106         {
107             scanf("%s", mp[i]);
108         }
109 
110         if(bfs()) output();
111         else printf("God please help our poor hero.\n");
112         printf("FINISH\n");
113     }
114     return 0;
115 }