towers.cpp: In function 'int max_towers(int, int, int)':
towers.cpp:22:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
22 | for(int i = 0; i < b.size(); i++) {
| ~~^~~~~~~~~~
/usr/bin/ld: /tmp/ccPP36HU.o: in function `main':
stub.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccXWv30U.o:towers.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccPP36HU.o: in function `main':
stub.cpp:(.text.startup+0x179): undefined reference to `init(int, std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status