speedrun.code: In function ‘void init(int)’:
speedrun.code:20:16: error: ISO C++ forbids declaration of ‘v’ with no type [-fpermissive]
   20 |     for (auto &v : adj[u]) {
      |                ^
speedrun.code:20:20: warning: range-based ‘for’ loops only available with ‘-std=c++11’ or ‘-std=gnu++11’
   20 |     for (auto &v : adj[u]) {
      |                    ^~~
speedrun.code:20:25: error: forming reference to reference type ‘std::vector<int>&’
   20 |     for (auto &v : adj[u]) {
      |                         ^
grader_speedrun.cpp: In function ‘int readvalue()’:
grader_speedrun.cpp:9:9: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
    9 |   fscanf(input, "%d", &val);
      |   ~~~~~~^~~~~~~~~~~~~~~~~~~