Compilare: user.c: In function ‘backtrack’: user.c:19:9: warning: implicit declaration of function ‘afisare’ [-Wimplicit-function-declaration] afisare(); ^ user.c: At top level: user.c:31:6: warning: conflicting types for ‘afisare’ [enabled by default] void afisare() { ^ user.c:19:9: note: previous implicit declaration of ‘afisare’ was here afisare(); ^ user.c: In function ‘main’: user.c:45:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&N,&K); ^