coins.cpp: In function 'std::vector<int> coin_flips(std::vector<int>, int)':
coins.cpp:10:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
10 | for(int i=0; i<b.size(); i++) x ^= b[i];
| ~^~~~~~~~~
coins.cpp: In function 'int find_coin(std::vector<int>)':
coins.cpp:21:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
21 | for(int i=0; i<b.size(); i++) coin ^= b[i];
| ~^~~~~~~~~