Compilare: user.cpp: In function ‘int main()’: user.cpp:23:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1;i<=n;++i) ^ user.cpp:28:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<m;++i) ^ user.cpp: In function ‘unsigned int sum(unsigned int)’: user.cpp:16:12: warning: ‘sum’ may be used uninitialized in this function [-Wmaybe-uninitialized] return sum; ^ user.cpp: In function ‘int main()’: user.cpp:37:35: warning: ‘sum’ may be used uninitialized in this function [-Wmaybe-uninitialized] output<<sum(b)-sum(a-1)<<"\n"; ^ user.cpp:37:35: warning: ‘sum’ may be used uninitialized in this function [-Wmaybe-uninitialized]