Compilare: user.cpp: In function ‘int main()’: user.cpp:91:32: 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:94:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (in, "%d", &c[i]); ^ user.cpp:98:36: 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:112:47: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (in, "%d %d", &e[i].a, &e[i].b); ^ user.cpp:108:15: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] dfs (r, 0); ^