books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:14:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
14 | for(ll i=0;i<P.size();i++) p[i]=P[i];
| ~^~~~~~~~~
books.cpp:15:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
15 | for(ll i=0;i<P.size();i++){
| ~^~~~~~~~~