#977322 (Go) No.738 平らな農地

提出ソース

結果

問題	No.738 平らな農地
ユーザー	草苺奶昔
提出日時	2024-04-25 14:29:35
言語	Go (1.22.1)
結果	AC
実行時間	121 ms / 2,000 ms
コード長	9,771 bytes
コンパイル時間	10,811 ms
コンパイル使用メモリ	229,728 KB
実行使用メモリ	11,396 KB
最終ジャッジ日時	2024-04-25 14:29:54
合計ジャッジ時間	18,405 ms
ジャッジサーバーID （参考情報）	judge1 / judge4

このコードへのチャレンジ
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テストケース

テストケース表示

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 6,812 KB
testcase_02	AC	1 ms 6,940 KB
testcase_03	AC	1 ms 6,940 KB
testcase_04	AC	1 ms 6,940 KB
testcase_05	AC	3 ms 6,944 KB
testcase_06	AC	3 ms 6,940 KB
testcase_07	AC	3 ms 6,944 KB
testcase_08	AC	2 ms 6,940 KB
testcase_09	AC	1 ms 6,944 KB
testcase_10	AC	1 ms 6,940 KB
testcase_11	AC	2 ms 6,944 KB
testcase_12	AC	2 ms 6,940 KB
testcase_13	AC	3 ms 6,944 KB
testcase_14	AC	2 ms 6,944 KB
testcase_15	AC	99 ms 9,016 KB
testcase_16	AC	98 ms 9,136 KB
testcase_17	AC	93 ms 8,880 KB
testcase_18	AC	95 ms 9,008 KB
testcase_19	AC	90 ms 8,736 KB
testcase_20	AC	98 ms 9,144 KB
testcase_21	AC	103 ms 8,880 KB
testcase_22	AC	100 ms 9,024 KB
testcase_23	AC	93 ms 8,880 KB
testcase_24	AC	90 ms 8,752 KB
testcase_25	AC	2 ms 6,940 KB
testcase_26	AC	2 ms 6,940 KB
testcase_27	AC	2 ms 6,940 KB
testcase_28	AC	1 ms 6,940 KB
testcase_29	AC	2 ms 6,944 KB
testcase_30	AC	2 ms 6,940 KB
testcase_31	AC	2 ms 6,940 KB
testcase_32	AC	2 ms 6,940 KB
testcase_33	AC	2 ms 6,940 KB
testcase_34	AC	2 ms 6,944 KB
testcase_35	AC	2 ms 6,940 KB
testcase_36	AC	1 ms 6,940 KB
testcase_37	AC	2 ms 6,940 KB
testcase_38	AC	2 ms 6,940 KB
testcase_39	AC	2 ms 6,944 KB
testcase_40	AC	2 ms 6,940 KB
testcase_41	AC	2 ms 6,940 KB
testcase_42	AC	2 ms 6,944 KB
testcase_43	AC	2 ms 6,944 KB
testcase_44	AC	1 ms 6,940 KB
testcase_45	AC	107 ms 9,140 KB
testcase_46	AC	97 ms 9,140 KB
testcase_47	AC	107 ms 9,136 KB
testcase_48	AC	92 ms 9,268 KB
testcase_49	AC	96 ms 9,264 KB
testcase_50	AC	102 ms 9,264 KB
testcase_51	AC	103 ms 9,136 KB
testcase_52	AC	98 ms 9,136 KB
testcase_53	AC	103 ms 9,136 KB
testcase_54	AC	105 ms 9,120 KB
testcase_55	AC	108 ms 9,140 KB
testcase_56	AC	102 ms 9,136 KB
testcase_57	AC	98 ms 9,140 KB
testcase_58	AC	104 ms 9,136 KB
testcase_59	AC	102 ms 9,268 KB
testcase_60	AC	102 ms 9,268 KB
testcase_61	AC	107 ms 9,240 KB
testcase_62	AC	98 ms 9,140 KB
testcase_63	AC	109 ms 9,136 KB
testcase_64	AC	105 ms 9,136 KB
testcase_65	AC	59 ms 7,816 KB
testcase_66	AC	62 ms 7,812 KB
testcase_67	AC	110 ms 8,640 KB
testcase_68	AC	101 ms 8,620 KB
testcase_69	AC	108 ms 8,508 KB
testcase_70	AC	121 ms 8,632 KB
testcase_71	AC	40 ms 6,940 KB
testcase_72	AC	58 ms 6,940 KB
testcase_73	AC	59 ms 6,940 KB
testcase_74	AC	64 ms 6,940 KB
testcase_75	AC	99 ms 8,724 KB
testcase_76	AC	107 ms 8,996 KB
testcase_77	AC	90 ms 8,512 KB
testcase_78	AC	102 ms 8,480 KB
testcase_79	AC	84 ms 7,824 KB
testcase_80	AC	83 ms 7,840 KB
testcase_81	AC	101 ms 8,508 KB
testcase_82	AC	99 ms 8,384 KB
testcase_83	AC	56 ms 8,260 KB
testcase_84	AC	53 ms 6,940 KB
testcase_85	AC	67 ms 6,940 KB
testcase_86	AC	62 ms 6,944 KB
testcase_87	AC	99 ms 11,396 KB
testcase_88	AC	93 ms 9,392 KB
testcase_89	AC	1 ms 6,944 KB
testcase_90	AC	1 ms 6,940 KB
testcase_91	AC	1 ms 6,940 KB

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ソースコード

raw source code

// 动态中位数，用两个平衡树(对顶)实现
// api:
// 1. Insert(x T)
// 2. Discard(x T) bool
// 3. Median() (low, high T)
// 4. DistToMedian() T
// 5. Size() int32

package main

import (
	"bufio"
	"fmt"
	"math/rand"
	"os"
	"sort"
)

func main() {
	yuki738()
	// test()
}

const INF int = 1e18

// No.738 平らな農地
// https://yukicoder.me/problems/no/738
// !滑动窗口所有数到中位数的距离和
func yuki738() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	var n, k int32
	fmt.Fscan(in, &n, &k)
	nums := make([]int, n)
	for i := int32(0); i < n; i++ {
		fmt.Fscan(in, &nums[i])
	}

	M := NewDynamicMedian()
	res := INF

	for i := int32(0); i < n; i++ {
		M.Insert(nums[i])
		if i >= k {
			M.Discard(nums[i-k])
		}
		if i >= k-1 {
			res = min(res, M.DistToMedian())
		}
	}
	fmt.Fprintln(out, res)
}

// 1e5 -> 100, 2e5 -> 200
const _LOAD int = 50

type S = int

type DynamicMedian struct {
	size     int32
	lower    *_sl
	upper    *_sl
	lowerSum S
	upperSum S
}

func NewDynamicMedian() *DynamicMedian {
	return &DynamicMedian{
		lower: NewSortedList(func(a, b S) bool { return a < b }),
		upper: NewSortedList(func(a, b S) bool { return a > b }),
	}
}

func (d *DynamicMedian) Insert(value S) {
	if d.size&1 == 0 {
		d.upper.Add(value)
		d.upperSum += value
	} else {
		d.lower.Add(value)
		d.lowerSum += value
	}
	d.size++
	d.balance()
}

func (d *DynamicMedian) Discard(value S) bool {
	if d.lower.Discard(value) {
		d.lowerSum -= value
		d.size--
		d.balance()
		return true
	} else if d.upper.Discard(value) {
		d.upperSum -= value
		d.size--
		d.balance()
		return true
	} else {
		return false
	}
}

// 返回中位数.如果元素个数为偶数,返回两个中位数.
func (d *DynamicMedian) Median() (low, high S) {
	if d.size == 0 {
		return
	}
	if d.size&1 == 0 {
		low = d.lower.Max()
		high = d.upper.Max()
	} else {
		low = d.upper.Max()
		high = low
	}
	return
}

func (d *DynamicMedian) DistToMedian() S {
	if d.size == 0 {
		return 0
	}
	low, _ := d.Median()
	sum1 := low*S(d.lower.Len()) - d.lowerSum
	sum2 := d.upperSum - low*S(d.upper.Len())
	return sum1 + sum2
}

func (d *DynamicMedian) Size() int32 { return d.size }

func (d *DynamicMedian) balance() {
	// 偶数个数时，|lower heap| == |upper heap|
	// 奇数个数时，|lower heap| + 1 == |upper heap|
	for d.lower.Len()+1 < d.upper.Len() {
		upperMin := d.upper._popLast()
		d.lower._appendLast(upperMin)
		d.lowerSum += upperMin
		d.upperSum -= upperMin
	}
	for d.lower.Len() > d.upper.Len() {
		lowerMin := d.lower._popLast()
		d.upper._appendLast(lowerMin)
		d.upperSum += lowerMin
		d.lowerSum -= lowerMin
	}

	// if d.size&1 == 0 {
	// 	if d.lower.size != d.upper.size {
	// 		panic("size error")
	// 	}
	// } else {
	// 	if d.lower.size+1 != d.upper.size {
	// 		panic("size error")
	// 	}
	// }

	if d.lower.Len() == 0 || d.upper.Len() == 0 {
		return
	}

	if d.lower.Max() > d.upper.Max() {
		upperMin := d.upper._popLast()
		d.lower.Add(upperMin)
		d.lowerSum += upperMin
		d.upperSum -= upperMin

		lowerMax := d.lower._popLast()
		d.upper.Add(lowerMax)
		d.upperSum += lowerMax
		d.lowerSum -= lowerMax
	}
}

// 使用分块+树状数组维护的有序序列.
type _sl struct {
	less              func(a, b S) bool
	size              int
	blocks            [][]S
	mins              []S
	tree              []int
	shouldRebuildTree bool
}

func NewSortedList(less func(a, b S) bool, elements ...S) *_sl {
	elements = append(elements[:0:0], elements...)
	res := &_sl{less: less}
	sort.Slice(elements, func(i, j int) bool { return less(elements[i], elements[j]) })
	n := len(elements)
	blocks := [][]S{}
	for start := 0; start < n; start += _LOAD {
		end := min(start+_LOAD, n)
		blocks = append(blocks, elements[start:end:end]) // !各个块互不影响, max参数也需要指定为end
	}
	mins := make([]S, len(blocks))
	for i, cur := range blocks {
		mins[i] = cur[0]
	}
	res.size = n
	res.blocks = blocks
	res.mins = mins
	res.shouldRebuildTree = true
	return res
}

func (sl *_sl) Add(value S) *_sl {
	sl.size++
	if len(sl.blocks) == 0 {
		sl.blocks = append(sl.blocks, []S{value})
		sl.mins = append(sl.mins, value)
		sl.shouldRebuildTree = true
		return sl
	}
	pos, index := sl._locRight(value)
	sl._updateTree(pos, 1)
	sl.blocks[pos] = append(sl.blocks[pos][:index], append([]S{value}, sl.blocks[pos][index:]...)...)
	sl.mins[pos] = sl.blocks[pos][0]
	// n -> load + (n - load)
	if n := len(sl.blocks[pos]); _LOAD+_LOAD < n {
		sl.blocks = append(sl.blocks[:pos+1], append([][]S{sl.blocks[pos][_LOAD:]}, sl.blocks[pos+1:]...)...)
		sl.mins = append(sl.mins[:pos+1], append([]S{sl.blocks[pos][_LOAD]}, sl.mins[pos+1:]...)...)
		sl.blocks[pos] = sl.blocks[pos][:_LOAD:_LOAD] // !注意max的设置(为了让左右互不影响)
		sl.shouldRebuildTree = true
	}
	return sl
}

func (sl *_sl) _appendLast(value S) *_sl {
	sl.size++
	if len(sl.blocks) == 0 {
		sl.blocks = append(sl.blocks, []S{value})
		sl.mins = append(sl.mins, value)
		sl.shouldRebuildTree = true
		return sl
	}
	pos := len(sl.blocks) - 1
	sl._updateTree(pos, 1)
	sl.blocks[pos] = append(sl.blocks[pos], value)
	// n -> load + (n - load)
	if n := len(sl.blocks[pos]); _LOAD+_LOAD < n {
		sl.blocks = append(sl.blocks[:pos+1], append([][]S{sl.blocks[pos][_LOAD:]}, sl.blocks[pos+1:]...)...)
		sl.mins = append(sl.mins[:pos+1], append([]S{sl.blocks[pos][_LOAD]}, sl.mins[pos+1:]...)...)
		sl.blocks[pos] = sl.blocks[pos][:_LOAD:_LOAD] // !注意max的设置(为了让左右互不影响)
		sl.shouldRebuildTree = true
	}
	return sl
}

func (sl *_sl) _popLast() S {
	sl.size--
	pos := len(sl.blocks) - 1
	res := sl.blocks[pos][len(sl.blocks[pos])-1]
	sl._updateTree(pos, -1)
	sl.blocks[pos] = sl.blocks[pos][:len(sl.blocks[pos])-1]
	if len(sl.blocks[pos]) == 0 {
		// !delete block
		sl.blocks = sl.blocks[:pos]
		sl.mins = sl.mins[:pos]
		sl.shouldRebuildTree = true
	}
	return res
}

func (sl *_sl) Discard(value S) bool {
	if len(sl.blocks) == 0 {
		return false
	}
	pos, index := sl._locRight(value)
	if index > 0 && sl.blocks[pos][index-1] == value {
		sl._delete(pos, index-1)
		return true
	}
	return false
}

func (sl *_sl) Max() S {
	if sl.size == 0 {
		panic("Max() called on empty SortedList")
	}
	lastBlock := sl.blocks[len(sl.blocks)-1]
	return lastBlock[len(lastBlock)-1]
}

func (sl *_sl) Len() int {
	return sl.size
}

func (sl *_sl) _delete(pos, index int) {
	// !delete element
	sl.size--
	sl._updateTree(pos, -1)
	sl.blocks[pos] = append(sl.blocks[pos][:index], sl.blocks[pos][index+1:]...)
	if len(sl.blocks[pos]) > 0 {
		sl.mins[pos] = sl.blocks[pos][0]
		return
	}

	// !delete block
	sl.blocks = append(sl.blocks[:pos], sl.blocks[pos+1:]...)
	sl.mins = append(sl.mins[:pos], sl.mins[pos+1:]...)
	sl.shouldRebuildTree = true
}

func (sl *_sl) _locRight(value S) (pos, index int) {
	if sl.size == 0 {
		return
	}

	// find pos
	left := 0
	right := len(sl.blocks)
	for left+1 < right {
		mid := (left + right) >> 1
		if sl.less(value, sl.mins[mid]) {
			right = mid
		} else {
			left = mid
		}
	}
	pos = left

	// find index
	cur := sl.blocks[pos]
	left = -1
	right = len(cur)
	for left+1 < right {
		mid := (left + right) >> 1
		if sl.less(value, cur[mid]) {
			right = mid
		} else {
			left = mid
		}
	}

	index = right
	return
}

func (sl *_sl) _buildTree() {
	sl.tree = make([]int, len(sl.blocks))
	for i := 0; i < len(sl.blocks); i++ {
		sl.tree[i] = len(sl.blocks[i])
	}
	tree := sl.tree
	for i := 0; i < len(tree); i++ {
		j := i | (i + 1)
		if j < len(tree) {
			tree[j] += tree[i]
		}
	}
	sl.shouldRebuildTree = false
}

func (sl *_sl) _updateTree(index, delta int) {
	if sl.shouldRebuildTree {
		return
	}
	tree := sl.tree
	for i := index; i < len(tree); i |= i + 1 {
		tree[i] += delta
	}
}

func (sl *_sl) _queryTree(end int) int {
	if sl.shouldRebuildTree {
		sl._buildTree()
	}
	tree := sl.tree
	sum := 0
	for end > 0 {
		sum += tree[end-1]
		end &= end - 1
	}
	return sum
}

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

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func test() {
	for i := 0; i < 1000; i++ {
		M := NewDynamicMedian()
		sortedNums := make([]int, 0)

		add := func(x int) {

			sortedNums = append(sortedNums, x)
			sort.Ints(sortedNums)
		}

		discard := func(x int) {

			for i, v := range sortedNums {
				if v == x {
					sortedNums = append(sortedNums[:i], sortedNums[i+1:]...)
					break
				}
			}
		}

		median := func() (low, high int) {
			if len(sortedNums) == 0 {
				return
			}
			n := len(sortedNums)
			if n&1 == 0 {
				low = sortedNums[n/2-1]
				high = sortedNums[n/2]
			} else {
				low = sortedNums[n/2]
				high = low
			}
			return
		}

		distToMedian := func() int {
			if len(sortedNums) == 0 {
				return 0
			}
			low, _ := median()
			res := 0
			for _, v := range sortedNums {
				res += abs(v - low)
			}
			return res
		}

		size := func() int {
			return len(sortedNums)
		}

		for j := 0; j < 1000; j++ {
			x := rand.Intn(10)

			// add
			M.Insert(x)
			add(x)

			// discard
			y := rand.Intn(10)
			M.Discard(y)
			discard(y)

			// median
			low, high := M.Median()
			low2, high2 := median()
			if low != low2 || high != high2 {
				fmt.Println("error")
				fmt.Println(low, high, low2, high2)
				fmt.Println(sortedNums)
				panic("error")
			}

			// distToMedian
			res := M.DistToMedian()
			res2 := distToMedian()
			if res != res2 {
				fmt.Println("error")
				fmt.Println(res, res2)
				fmt.Println(sortedNums)
				panic("error")
			}

			// size
			sz := M.Size()
			sz2 := size()
			if sz != int32(sz2) {
				fmt.Println("error")
				fmt.Println(sz, sz2)
				fmt.Println(sortedNums)
				panic("error")
			}

		}

	}
	fmt.Println("pass")
}