books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:5:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
5 | #define rng(i,l,r) for(int i=(l); i<(r); i++)
| ^
books.cpp:31:2: note: in expansion of macro 'rng'
31 | rng(i,1,seg.size()){
| ^~~
books.cpp:4:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
4 | #define rep(i,n) for(int i=0; i<(n); i++)
| ^
books.cpp:39:2: note: in expansion of macro 'rep'
39 | rep(i,re.size()-1){
| ^~~