shoes.cpp: In function 'long long int count_swaps(const std::vector<int>&)':
shoes.cpp:48:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
48 | for (int j = 0; j < same_size[i].size() / 2; j++) {
| ~~^~~~~~~~~~~~~~~~~~~~~~~~~
shoes.cpp:65:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
65 | for (auto [l, r] : matchings) {
| ^
/usr/bin/ld: /tmp/ccOh4PeE.o: in function `main':
grader.cpp:(.text.startup+0x29d): undefined reference to `count_swaps(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status