boxes.cpp: In function 'void build(std::vector<int>&, int, int, std::vector<long long int>&)':
boxes.cpp:12:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | for (int i = 0; i < v.size(); i++){
| ~~^~~~~~~~~~
boxes.cpp:11:8: warning: unused variable 'cost' [-Wunused-variable]
11 | ll cost = 0, prizes = K;
| ^~~~
boxes.cpp:11:18: warning: unused variable 'prizes' [-Wunused-variable]
11 | ll cost = 0, prizes = K;
| ^~~~~~
boxes.cpp: In function 'long long int delivery(int, int, int, int*)':
boxes.cpp:27:16: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
27 | N = lf.size();
| ~~~~~~~^~