Compilare: user.c: In function ‘pop’: user.c:26:5: warning: control reaches end of non-void function [-Wreturn-type] } //sf pop_back ^ user.c: In function ‘main’: user.c:41:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&n,&m); ^ user.c:42:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&c); ^ user.c:43:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&c); ^ user.c:52:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&c); ^