stations.cpp: In function 'void dfs(int, int)':
stations.cpp:12:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | for(int i = 0; i < haha[a].size(); i++) {
| ~~^~~~~~~~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:42:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
42 | for(int i = 0; i < c.size(); i++) {
| ~~^~~~~~~~~~
stations.cpp:43:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
43 | if(c[i] <= t && (i == c.size()-1 || c[i+1] > t)) {
| ~~^~~~~~~~~~~~~
stations.cpp:53:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
53 | for(int i = 0; i < c.size(); i++) {
| ~~^~~~~~~~~~
stations.cpp:54:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
54 | if(c[i] <= t && (i == c.size()-1 || c[i+1] > t)) {
| ~~^~~~~~~~~~~~~
stations.cpp:60:1: warning: control reaches end of non-void function [-Wreturn-type]
60 | }
| ^