Compilare: user.cpp: In function ‘int main()’: user.cpp:103:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%d%d%d%d%*c",&n,&m,&st,&dr); ^ user.cpp:110:17: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets (s,15,f); ^ user.cpp:124:20: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets (s,500010,f); ^ user.cpp: In function ‘void remake()’: user.cpp:90:23: warning: ‘lastnod’ may be used uninitialized in this function [-Wmaybe-uninitialized] trece[ k].y=lastnod; ^ user.cpp: In function ‘int main()’: user.cpp:90:23: warning: ‘lastnod’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:87:6: note: ‘lastnod’ was declared here int lastnod,l=L; ^