Compilare: user.cpp: In function ‘int main()’: user.cpp:18:23: warning: format ‘%s’ expects argument of type ‘char*’, but argument 3 has type ‘char (*)[100010]’ [-Wformat=] fscanf(f, "%s", &a); ^ user.cpp:24:32: warning: NULL used in arithmetic [-Wpointer-arith] while (!feof(f) && a[i] != NULL) ^ user.cpp:21:16: warning: unused variable ‘j’ [-Wunused-variable] int i = 0, j = 0; ^ user.cpp:18:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%s", &a); ^ user.cpp:23:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "\n%c", &c); ^ user.cpp:26:61: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fprintf(g, "%d ", i+1), i++, fscanf(f, "%c", &c); ^