foo.cc: In function 'void dfs(int, int)':
foo.cc:13:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |     for(int i=0; i<v[now].size(); i++)
      |                  ~^~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:98:13: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
   98 |             while(d[x]>d[z]+1)
      |             ^~~~~
foo.cc:100:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
  100 |    cout<<sum[z]-sum[x]<<endl;
      |    ^~~~

Found 4 testcases.
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