supertrees.cpp: In function 'void build(std::vector<std::vector<int> >&)':
supertrees.cpp:13:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
13 | for (int i = 0; i < b.size(); ++i) {
| ~~^~~~~~~~~~
supertrees.cpp:14:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
14 | for (int j = 0; j < b[i].size(); ++j) {
| ~~^~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccXr9FKx.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccIelLRv.o:supertrees.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccXr9FKx.o: in function `main':
grader.cpp:(.text.startup+0x38a): undefined reference to `construct(std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >)'
collect2: error: ld returned 1 exit status