Compilare: user.cpp: In function ‘void dijkstra()’: user.cpp:30:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<gf[node].size(); ++i){ ^ In file included from /usr/include/c++/4.8/cassert:43:0, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:33, from user.cpp:1: user.cpp: In function ‘int main()’: user.cpp:63:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] assert(x >= 1 && x <= e.size()); ^ user.cpp:88:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<ans.size(); ++i) g << ans[i] << " "; ^