Compilare: user.cpp: In function ‘int main()’: user.cpp:177:22: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(f,1,MAX,IN); ^ user.cpp:110:27: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] int lw=p,hi=N,mid,last; ^~~~ user.cpp:110:27: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:86:70: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] Val+=Cost[dir][type][r]-Cost[dir][type][l-1]-1LL*(Cnt[type][r]-Cnt[type][l-1])*(l-1); ~~~~~~~~~~~^ user.cpp:110:27: note: ‘last’ was declared here int lw=p,hi=N,mid,last; ^~~~ user.cpp:88:85: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] Val+=Cost[dir][type][l]-Cost[dir][type][r+1]-1LL*(Cnt[type][r]-Cnt[type][l-1])*(N-r); ~~~~~~~~~~~~~^ user.cpp:110:27: note: ‘last’ was declared here int lw=p,hi=N,mid,last; ^~~~