train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:44:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
44 | for(int i=0;i<u.size();i++)
| ~^~~~~~~~~
train.cpp:48:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
48 | for(int i=0;i<a.size();i++) {
| ~^~~~~~~~~
train.cpp:50:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
50 | for(int j=0;j<a.size();j++)
| ~^~~~~~~~~
train.cpp:59:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
59 | for(int j=0;j<a.size();j++) {
| ~^~~~~~~~~
train.cpp:66:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
66 | for(int j=0;j<a.size();j++) {
| ~^~~~~~~~~