no gui output

[ambglh]

g@g:/A_star/a-star$ ./app
Generate path ...
20 20
19 19
18 18
17 17
16 16
15 15
14 14
13 13
12 12
11 11
10 10
9 9
8 8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
0 0
g@g:/A_star/a-star$

[Pha1ton]

I also met this problem when running this code. The preview pictures are misunderstanding and confusing. I can't find any code which is used to visualize the progress of searching.