parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:10:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
10 | for(i=1;i<V.size();i++)if(V[i].first!=V[i-1].first+2)return 0;
| ~^~~~~~~~~
parks.cpp:12:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | for(i=1;i<V.size();i++)
| ~^~~~~~~~~
parks.cpp:7:15: warning: unused variable 'j' [-Wunused-variable]
7 | int n, i, j, k;n=x.size();
| ^
parks.cpp:7:18: warning: unused variable 'k' [-Wunused-variable]
7 | int n, i, j, k;n=x.size();
| ^