Compilare: user.cpp: In function ‘int main()’: user.cpp:29:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<h[r].size() && h[r][j]!=x;j++); ^ user.cpp:30:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j==h[r].size() || h[r][j]!=x)h[r].push_back(x); ^ user.cpp:36:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<h[r].size() && h[r][j]!=x;j++); ^ user.cpp:37:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j<h[r].size() && h[r][j]==x) cnt++; ^