Compilare: user.cpp: In function ‘int main()’: user.cpp:38:21: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(S,Nmax,in); ^ user.cpp:44:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d\n",&nr); ^ user.cpp:49:32: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(mat[x-'A']+1,Nmax,in); ^ user.cpp:54:36: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(mat[x-'A']+1,Nmax,in); ^ user.cpp: In function ‘int fact(char)’: user.cpp:102:1: warning: control reaches end of non-void function [-Wreturn-type] } ^