books.cpp: In function 'long long int aabs(int)':
books.cpp:9:12: warning: unused variable 'xx' [-Wunused-variable]
long long xx = (long long)(x);
^~
books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:17:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<p.size();i++)
~^~~~~~~~~
books.cpp:32:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<p.size();i++)
~^~~~~~~~~
books.cpp:41:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if(k==p.size())return 0;
~^~~~~~~~~~