package main import ( "container/heap" "fmt" "math" ) func main() { var n, m, src int fmt.Scan(&n, &m, &src) adj := make([][]int, n) length := make([][]int, n) for i := range length { length[i] = make([]int, n) } for i := 0; i < m; i++ { var u, v, l int fmt.Scan(&u, &v, &l) adj[u] = append(adj[u], v) length[u][v] = l } dist, prev := dijkstra(adj, length, src) fmt.Println(dist) fmt.Println(prev) } type minHeap [][2]int func (h minHeap) Len() int { return len(h) } func (h minHeap) Less(i, j int) bool { return h[i][0] < h[j][0] } func (h minHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] } func (h *minHeap) Push(x interface{}) { *h = append(*h, x.([2]int)) } func (h *minHeap) Pop() interface{} { l := len(*h) x := (*h)[l-1] *h = (*h)[:l-1] return x } func dijkstra(adj [][]int, length [][]int, src int) (dist []int, prev []int) { n := len(adj) dist = make([]int, n) prev = make([]int, n) for i := 0; i < n; i++ { dist[i] = math.MaxInt32 prev[i] = -1 } dist[src] = 0 var mh minHeap heap.Push(&mh, [2]int{0, src}) for mh.Len() != 0 { u := heap.Pop(&mh).([2]int) if dist[u[1]] < u[0] { continue } for _, v := range adj[u[1]] { alt := u[0] + length[u[1]][v] if alt < dist[v] { dist[v] = alt prev[v] = u[1] heap.Push(&mh, [2]int{alt, v}) } } } return }