Compilare: user.cpp: In function ‘void Build()’: user.cpp:15:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘void Solve()’: user.cpp:65:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(val == X) break; ^ user.cpp:66:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(val < X) st = mid+1; ^ user.cpp:69:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(val != X) fout << "-1\n"; ^ user.cpp:46:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,level = 0; ^ user.cpp: In function ‘int main()’: user.cpp:72:23: warning: ‘mid’ may be used uninitialized in this function [-Wmaybe-uninitialized] Rec(level,mid); ^ user.cpp:47:25: note: ‘mid’ was declared here long long val,st,dr,mid; ^