优先队列+bfs

AC Code 
  1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 using namespace std;
  5 int vis[25][25];
  6 int map[25][25],tmp[25][25];
  7 int k;
  8 int x1,y1,x2,y2,r,c;
  9 struct 
 10 {
 11     int x,y,val;
 12 }a[505];
 13 void down()
 14 {
 15     int  x=a[k].x,y=a[k].y,val=a[k].val,i=1,j=2;
 16     k--;
 17     while(j<=k){
 18         if(a[j].val>a[j+1].val&&j+1<=k)
 19         j++;
 20         if(val>a[j].val){
 21             a[i].x=a[j].x;
 22             a[i].y=a[j].y;
 23             a[i].val=a[j].val;
 24             i=j;
 25             j=2*i;
 26         }
 27         else
 28         break;
 29     }
 30     a[i].x=x;
 31     a[i].y=y;
 32     a[i].val=val;
 33 }
 34 void up()
 35 {
 36     int i=k,x=a[k].x,y=a[k].y,val=a[k].val;
 37     while(i>1){
 38         if(a[i/2].val>val){
 39             a[i].x=a[i/2].x;
 40             a[i].y=a[i/2].y;
 41             a[i].val=a[i/2].val;
 42             i/=2;
 43         }
 44         else
 45         break;
 46     }
 47     a[i].x=x;
 48     a[i].y=y;
 49     a[i].val=val;
 50 }
 51 void bfs()
 52 {
 53     if(vis[x2][y2]==1||k==0)
 54     return;
 55     int x=a[1].x,y=a[1].y,val=a[1].val;
 56     if(vis[x-1][y]==0&&x-1>=0){
 57         map[x-1][y]=val+map[x-1][y];
 58         vis[x-1][y]=1;
 59         a[++k].x=x-1;
 60         a[k].y=y;
 61         a[k].val=map[x-1][y];
 62         up();
 63     }
 64     if(vis[x+1][y]==0&&x+1<r){
 65         map[x+1][y]=val+map[x+1][y];
 66         vis[x+1][y]=1;
 67         a[++k].x=x+1;
 68         a[k].y=y;
 69         a[k].val=map[x+1][y];
 70         up();
 71     }
 72     if(vis[x][y-1]==0&&y-1>=0){
 73         map[x][y-1]=val+map[x][y-1];
 74         vis[x][y-1]=1;
 75         a[++k].x=x;
 76         a[k].y=y-1;
 77         a[k].val=map[x][y-1];
 78         up();
 79     }
 80     if(vis[x][y+1]==0&&y+1<c){
 81         map[x][y+1]=val+map[x][y+1];
 82         vis[x][y+1]=1;
 83         a[++k].x=x;
 84         a[k].y=y+1;
 85         a[k].val=map[x][y+1];
 86         up();
 87     }
 88     down();
 89     bfs();
 90 }
 91 int main()
 92 {
 93     int cas=1;
 94     while(~scanf("%d%d",&r,&c)){
 95         int p,s,t;
 96         char op;
 97         scanf("%d%d%d",&p,&s,&t);
 98         getchar();
 99         memset(vis,0,sizeof(vis));
100         for(int i=0;i<r;i++){
101         for(int j=0;j<c;j++){
102             scanf("%c",&op);
103             if(op=='T')
104             map[i][j]=t;
105             else if(op=='.')
106             map[i][j]=s;
107             else if(op=='#')
108             map[i][j]=p;
109             else{
110             map[i][j]=-1;
111             vis[i][j]=1;
112             }
113             tmp[i][j]=map[i][j];
114         }
115             getchar();
116         }
117         scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
118         printf("Case %d: ",cas++);
119         if(vis[x2][y2]==1){
120             printf("-1\n");
121             continue;
122         }
123         vis[x1][y1]=1;
124         k=1;
125         a[1].x=x1;
126         a[1].y=y1;
127         a[1].val=map[x1][y1];
128         bfs();
129         if(vis[x2][y2]==0)
130         printf("-1\n");
131         else
132         printf("%d\n",map[x2][y2]-tmp[x1][y1]);
133     }
134     return 0;
135 }