Compilare: user.cpp: In function ‘int main()’: user.cpp:72:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < V[node].size() && step <= p; step <<= 1, ++k) ^ user.cpp:40:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(STR, 1, S_MAX, f); ^