Compilare: user.cpp: In function ‘int main()’: user.cpp:25:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = v.size() - 1 ; i >= v.size() - b ; i-- ) ^ user.cpp:30:71: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = v.size() - sterse ; i <= v.size() - sterse - 1 + b ; i++ ) ^ user.cpp:32:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = v.size() - sterse + b ; i < v.size() ; i++ ) ^