Compilare: user.c:2: warning: built-in function ‘index’ declared as non-function user.c: In function ‘max_length’: user.c:24: warning: unused variable ‘j’ user.c: In function ‘main’: user.c:71: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:73: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:83: warning: control reaches end of non-void function user.c: In function ‘b_search’: user.c:21: warning: control reaches end of non-void function