treearray.cpp: In function 'void dfs(int, int)':
treearray.cpp:79:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<nei[u].size(); i++)
~^~~~~~~~~~~~~~
treearray.cpp: In function 'int main()':
treearray.cpp:20:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &u, &v);
~~~~~^~~~~~~~~~~~~~~~
treearray.cpp:31:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", a+i);
~~~~~^~~~~~~~~~~
treearray.cpp:35:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &type);
~~~~~^~~~~~~~~~~~~
treearray.cpp:38:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &pos, &v);
~~~~~^~~~~~~~~~~~~~~~~~
treearray.cpp:43:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d%d", &L, &R, &v);
~~~~~^~~~~~~~~~~~~~~~~~~~~~