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:47:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
47 | for(int i = 0; i < c.size(); i++) {
| ~~^~~~~~~~~~
stations.cpp:48:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
48 | if(c[i] <= t && (i == c.size()-1 || c[i+1] > t)) {
| ~~^~~~~~~~~~~~~
stations.cpp:58:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
58 | for(int i = 1; i < c.size(); i++) {
| ~~^~~~~~~~~~
stations.cpp:59:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
59 | if(c[i] <= t && (i == c.size()-1 || c[i+1] > t)) {
| ~~^~~~~~~~~~~~~
stations.cpp:65:1: warning: control reaches end of non-void function [-Wreturn-type]
65 | }
| ^