Compilare: user.c: In function ‘read’: user.c:22: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:24: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:25: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:27: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:30: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c: In function ‘compare_cost’: user.c:42: warning: array subscript has type ‘char’ user.c:44: warning: array subscript has type ‘char’ user.c:44: warning: array subscript has type ‘char’ user.c:44: warning: array subscript has type ‘char’ user.c:44: warning: array subscript has type ‘char’ user.c:46: warning: array subscript has type ‘char’ user.c:46: warning: array subscript has type ‘char’ user.c:46: warning: array subscript has type ‘char’ user.c:46: warning: array subscript has type ‘char’ user.c:48: warning: array subscript has type ‘char’ user.c:48: warning: array subscript has type ‘char’ user.c:48: warning: array subscript has type ‘char’ user.c:48: warning: array subscript has type ‘char’ user.c:49: warning: array subscript has type ‘char’ user.c:49: warning: array subscript has type ‘char’ user.c:49: warning: array subscript has type ‘char’ user.c:49: warning: array subscript has type ‘char’ user.c: In function ‘solve’: user.c:141: warning: unused variable ‘j’ user.c: In function ‘print’: user.c:161: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result