train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:23:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | for(int i=0;i<u.size();i++)
| ~^~~~~~~~~
train.cpp:26:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
26 | for(st=0;st<a.size();st++) {
| ~~^~~~~~~~~
train.cpp:30:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
30 | for(int i=0;i<a.size();i++) {
| ~^~~~~~~~~
train.cpp:33:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
33 | for(int k=0;k<a.size();k++) {
| ~^~~~~~~~~
train.cpp:41:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
41 | for(int k=0;k<a.size();k++) {
| ~^~~~~~~~~
train.cpp:43:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
43 | for(int k=0;k<a.size();k++) {
| ~^~~~~~~~~