Compilare: user.cpp: In function ‘int find_prev(int)’: user.cpp:58:18: warning: ‘mid’ may be used uninitialized in this function [-Wmaybe-uninitialized] return (mid-1); ^ user.cpp: In function ‘int main()’: user.cpp:58:18: warning: ‘mid’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:46:17: note: ‘mid’ was declared here int l=1,r=K,mid; ^