#414438 (Go) No.160 最短経路のうち辞書順最小

• 問題: No.160 最短経路のうち辞書順最小
• ユーザー: maguroguma
• 提出日時: 2020-01-05 15:06:15
• 言語: Go (1.22.1)
• 結果: AC
• 実行時間: 8 ms / 5,000 ms
• コード長: 9,200 bytes
• コンパイル時間: 11,793 ms
• コンパイル使用メモリ: 235,104 KB
• 実行使用メモリ: 6,820 KB
• 最終ジャッジ日時: 2024-11-22 21:58:37
• 合計ジャッジ時間: 12,858 ms
• ジャッジサーバーID （参考情報）: judge2 / judge3

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 6,816 KB
testcase_01	AC	1 ms; 6,820 KB
testcase_02	AC	1 ms; 6,820 KB
testcase_03	AC	1 ms; 6,816 KB
testcase_04	AC	3 ms; 6,820 KB
testcase_05	AC	4 ms; 6,820 KB
testcase_06	AC	6 ms; 6,820 KB
testcase_07	AC	2 ms; 6,816 KB
testcase_08	AC	3 ms; 6,816 KB
testcase_09	AC	2 ms; 6,816 KB
testcase_10	AC	2 ms; 6,816 KB
testcase_11	AC	2 ms; 6,816 KB
testcase_12	AC	2 ms; 6,820 KB
testcase_13	AC	2 ms; 6,816 KB
testcase_14	AC	2 ms; 6,816 KB
testcase_15	AC	2 ms; 6,816 KB
testcase_16	AC	2 ms; 6,816 KB
testcase_17	AC	3 ms; 6,816 KB
testcase_18	AC	2 ms; 6,816 KB
testcase_19	AC	2 ms; 6,816 KB
testcase_20	AC	2 ms; 6,816 KB
testcase_21	AC	2 ms; 6,816 KB
testcase_22	AC	2 ms; 6,820 KB
testcase_23	AC	2 ms; 6,816 KB
testcase_24	AC	3 ms; 6,816 KB
testcase_25	AC	2 ms; 6,816 KB
testcase_26	AC	2 ms; 6,820 KB
testcase_27	AC	1 ms; 6,816 KB
testcase_28	AC	8 ms; 6,820 KB
testcase_29	AC	2 ms; 6,820 KB

ソースコード

package main

import (
	"bufio"
	"container/heap"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	ReadString = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintIntsLine returns integers string delimited by a space.
func PrintInts64Line(A ...int64) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.FormatInt(A[i], 10) // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintDebug is wrapper of fmt.Fprintf(os.Stderr, format, a...)
func PrintDebug(format string, a ...interface{}) {
	fmt.Fprintf(os.Stderr, format, a...)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*
ASCII code

ASCII   10進数  ASCII   10進数  ASCII   10進数
!       33      "       34      #       35
$       36      %       37      &       38
'       39      (       40      )       41
*       42      +       43      ,       44
-       45      .       46      /       47
0       48      1       49      2       50
3       51      4       52      5       53
6       54      7       55      8       56
9       57      :       58      ;       59
<       60      =       61      >       62
?       63      @       64      A       65
B       66      C       67      D       68
E       69      F       70      G       71
H       72      I       73      J       74
K       75      L       76      M       77
N       78      O       79      P       80
Q       81      R       82      S       83
T       84      U       85      V       86
W       87      X       88      Y       89
Z       90      [       91      \       92
]       93      ^       94      _       95
`       96      a       97      b       98
c       99      d       100     e       101
f       102     g       103     h       104
i       105     j       106     k       107
l       108     m       109     n       110
o       111     p       112     q       113
r       114     s       115     t       116
u       117     v       118     w       119
x       120     y       121     z       122
{       123     |       124     }       125
~       126             127
*/

/*******************************************************************/

const (
	// General purpose
	MOD          = 1000000000 + 7
	ALPHABET_NUM = 26
	INF_INT64    = math.MaxInt64
	INF_BIT60    = 1 << 60
	INF_INT32    = math.MaxInt32
	INF_BIT30    = 1 << 30
	NIL          = -1

	// for dijkstra, prim, and so on
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

var n, m, s, g int

func main() {
	n, m, s, g = ReadInt4()
	for i := 0; i < m; i++ {
		a, b, c := ReadInt3()
		G[a] = append(G[a], Edge{to: b, cost: c})
		G[b] = append(G[b], Edge{to: a, cost: c})
	}

	// 始点からの辞書順最小なので、逆から復元するのは無理（頑張ればできる？）
	// dp := dijkstra(s)
	// answers := []int{g}
	// total := dp[g]
	// cid := g
	// for total > 0 {
	// 	nid := INF_BIT30
	// 	ecost := -1
	// 	for _, e := range G[cid] {
	// 		if total-e.cost == dp[e.to] && nid > e.to {
	// 			nid = e.to
	// 			ecost = e.cost
	// 		}
	// 	}

	// 	answers = append(answers, nid)
	// 	total -= ecost
	// 	cid = nid
	// }

	// answers = Reverse(answers)
	// fmt.Println(PrintIntsLine(answers...))

	dp := dijkstra(g)
	answers := []int{s}
	total := dp[s]
	cid := s
	for total > 0 {
		nid := INF_BIT30
		ecost := -1
		for _, e := range G[cid] {
			if total-e.cost == dp[e.to] && nid > e.to {
				nid = e.to
				ecost = e.cost
			}
		}

		answers = append(answers, nid)
		total -= ecost
		cid = nid
	}
	fmt.Println(PrintIntsLine(answers...))
}

func dijkstra(sid int) []int {
	dp, colors, parents := make([]int, NUM), make([]int, NUM), make([]int, NUM)
	for i := 0; i < NUM; i++ {
		dp[i], colors[i], parents[i] = INF_BIT30, WHITE, -1
	}

	temp := make(VertexPQ, 0, 100000+1)
	pq := &temp
	heap.Init(pq)

	dp[sid], colors[sid] = 0, GRAY
	heap.Push(pq, &Vertex{id: sid, cost: dp[sid]})

	for pq.Len() > 0 {
		cv := heap.Pop(pq).(*Vertex)
		colors[cv.id] = BLACK

		if dp[cv.id] < cv.cost {
			continue
		}

		for _, e := range G[cv.id] {
			if colors[e.to] == BLACK {
				continue
			}

			if dp[e.to] > dp[cv.id]+e.cost {
				dp[e.to] = dp[cv.id] + e.cost
				colors[e.to] = GRAY
				parents[e.to] = cv.id
				heap.Push(pq, &Vertex{id: e.to, cost: dp[e.to]})
			}
		}
	}

	return dp
}

type Edge struct {
	to, cost int
}

const NUM = 200 + 5

var G [NUM][]Edge

type Vertex struct {
	id, cost int
}
type VertexPQ []*Vertex

func (pq VertexPQ) Len() int           { return len(pq) }
func (pq VertexPQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost } // <: ASC, >: DESC
func (pq VertexPQ) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}
func (pq *VertexPQ) Push(x interface{}) {
	item := x.(*Vertex)
	*pq = append(*pq, item)
}
func (pq *VertexPQ) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	*pq = old[0 : n-1]
	return item
}

// how to use
// temp := make(VertexPQ, 0, 100000+1)
// pq := &temp
// heap.Init(pq)
// heap.Push(pq, &Vertex{pri: intValue})
// popped := heap.Pop(pq).(*Vertex)

/*
- まずは全探索を検討しましょう
- MODは最後にとりましたか？
- ループを抜けた後も処理が必要じゃありませんか？
- 和・積・あまりを求められたらint64が必要ではありませんか？
- いきなりオーバーフローはしていませんか？
- MOD取る系はint64必須ですよ？
*/

/*******************************************************************/