2022-01-06：N个结点之间，表世界存在双向通行的道路，里

package main

import (
    "fmt"
    "math"
    "sort"
)

func main() {
    roads := [][]int{{1}, {2}, {0}}
    gates := [][]int{{1}, {2}, {0}}
    ret := fast(3, roads, gates)
    fmt.Println(ret)
}

// 城市编号从0开始，编号对应0~n-1
// roads[i]是一个数组，表示i能走路达到的城市有哪些，每条路都花费1分钟
// gates[i]是一个数组，表示i能传送达到的城市有哪些
// 返回从0到n-1的最少用时
func fast(n int, roads, gates [][]int) int {
    distance := make([][]int, 2)
    for i := 0; i < 2; i++ {
        distance[i] = make([]int, n)
    }
    // 因为从0开始走，所以distance[0][0] = 0, distance[1][0] = 0
    // distance[0][i] -> 0 : 前一个城市到达i，是走路的方式, 最小代价，distance[0][i]
    // distance[1][i] -> 1 : 前一个城市到达i，是传送的方式, 最小代价，distance[1][i]
    for i := 1; i < n; i++ {
        distance[0][i] = math.MaxInt64
        distance[1][i] = math.MaxInt64
    }
    // 小根堆，根据距离排序，距离小的点，在上！
    //PriorityQueue<Node> heap = new PriorityQueue<>((a, b) -> a.cost - b.cost);
    heap := make([]*Node, 0)
    //heap.add(new Node(0, 0, 0));
    heap = append(heap, NewNode(0, 0, 0))
    //boolean[][] visited = new boolean[2][n];
    visited := make([][]bool, 2)
    for i := 0; i < 2; i++ {
        visited[i] = make([]bool, n)
    }
    for len(heap) > 0 {
        sort.Slice(heap, func(i, j int) bool {
            return heap[i].cost < heap[j].cost
        })
        //Node cur = heap.poll();
        cur := heap[0]
        heap = heap[1:]
        if visited[cur.preTransfer][cur.city] {
            continue
        }
        visited[cur.preTransfer][cur.city] = true
        // 走路的方式
        for _, next := range roads[cur.city] {
            if distance[0][next] > cur.cost+1 {
                distance[0][next] = cur.cost + 1
                heap = append(heap, NewNode(0, next, distance[0][next]))
            }
        }
        // 传送的方式
        if cur.preTransfer == 0 {
            for _, next := range gates[cur.city] {
                if distance[1][next] > cur.cost {
                    distance[1][next] = cur.cost
                    heap = append(heap, NewNode(1, next, distance[1][next]))
                }
            }
        }
    }
    return getMin(distance[0][n-1], distance[1][n-1])
}

type Node struct {
    preTransfer int
    city        int
    cost        int
}

func NewNode(a, b, c int) *Node {
    res := &Node{}
    res.preTransfer = a
    res.city = b
    res.cost = c
    return res
}

func getMin(a, b int) int {
    if a < b {
        return a
    } else {
        return b
    }
}