Compilare: main.cpp: In function 'int bfs(int, int)': main.cpp:130:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[Q[p]].size();i++) ~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:156:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d%d",&n,&m,&q); ^ main.cpp:158:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%s",s[i]+1); ^ main.cpp:189:40: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d%d%d",&xs,&ys,&xd,&yd); ^