books.cpp: In function 'void solve(int, int, long long int, int)':
books.cpp:26:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long unsigned int'} and 'long long int' [-Wsign-compare]
26 | if(SUM(1 , K) > 2 * A) return impossible();
| ~~~~~~~~~~~^~~~~~~
books.cpp:27:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long unsigned int'} and 'long long int' [-Wsign-compare]
27 | if(SUM(1 , K) >= A)
| ~~~~~~~~~~~^~~~
books.cpp:38:31: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long unsigned int'} and 'long long int' [-Wsign-compare]
38 | if(SUM(1 , K - 1) + GET(md) >= A) r = md;
| ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
books.cpp:42:39: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long unsigned int'} and 'long long int' [-Wsign-compare]
42 | if(r <= N && SUM(1 , K - 1) + GET(r) <= 2 * A)
| ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
books.cpp:51:44: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long unsigned int'} and 'long long int' [-Wsign-compare]
51 | if(SUM(1 , ln) + SUM(l - K + ln + 1 , l) >= A)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~