Compilare: user.cpp: In function ‘int main()’: user.cpp:40:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[x].size(); ++i) ^ user.cpp:59:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < arb[nr][x].size(); ++i) ^ user.cpp:77:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < arb[nr][x].size(); ++i) ^ user.cpp:19:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ user.cpp:23:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &x, &y); ^ user.cpp:53:22: warning: ‘nmax’ may be used uninitialized in this function [-Wmaybe-uninitialized] vis[nmax] = c; ^