Class cmp

code/graph/dijkstra.cpp:2–5

int *dist, *dad;
struct cmp {
  bool operator()(int a, int b) const {
    return dist[a] != dist[b] ? dist[a] < dist[b] : a < b; }
};
pair<int*, int*> dijkstra(int n, int s, vii *adj) {
  dist = new int[n];
  dad = new int[n];