Compilare: main.c: In function 'back': main.c:6:5: warning: type of 'n' defaults to 'int' [-Wimplicit-int] int back(n,i){ ^~~~ main.c:6:5: warning: type of 'i' defaults to 'int' [-Wimplicit-int] main.c:25:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.c: In function 'main': main.c:30:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^~~~~~~~~~~~~~~~~~~