Compilare: user.cpp: In function ‘void read()’: user.cpp:23:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (unsigned int i = 1; i <= m; i++) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:32:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < graph[node].size(); i++) ^ user.cpp: In function ‘void solve()’: user.cpp:40:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (unsigned int i = 1; i <= n; i++) ^ user.cpp: In function ‘void write()’: user.cpp:46:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (unsigned int i = 1; i <= n; i++) ^ user.cpp: In function ‘void read()’: user.cpp:22:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d", &n, &m); ^ user.cpp:24:46: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d", &x, &y), add(x, y); ^