2023-06-18：给定一个长度为N的一维数组scores, 代表0~N-1号员工的初始得分，

scores[i] = a, 表示i号员工一开始得分是a，

给定一个长度为M的二维数组operations,

operations[i] = {a, b, c}。

表示第i号操作为 :

如果a==1, 表示将目前分数<b的所有员工，分数改成b，c这个值无用，

如果a==2, 表示将编号为b的员工，分数改成c，

所有操作从0~M-1, 依次发生。

返回一个长度为N的一维数组ans，表示所有操作做完之后，每个员工的得分是多少。

1 <= N <= 10的6次方，

1 <= M <= 10的6次方，

0 <= 分数 <= 10的9次方。

来自TikTok美国笔试。

答案2023-06-18：

具体步骤如下：

1.创建一个长度为N的一维数组scores，表示每个员工的初始得分。

2.创建一个长度为M的二维数组operations，表示操作序列。

3.定义一个函数operateScores2来处理操作序列。

4.初始化一个节点数组nodes，用于存储每个员工的节点信息。

5.初始化一个空的得分和桶的映射表scoreBucketMap。

6.遍历scores数组，为每个得分值创建一个桶，并将对应的员工节点添加到桶中。

7.遍历operations数组，处理每个操作。

8.对于类型为1的操作，获取小于当前得分的最大得分值floorKeyV，然后将它们的桶合并到新的得分值对应的桶中。

9.对于类型为2的操作，获取该员工节点，并将其从原来的桶中移除，然后添加到新的得分值对应的桶中。

10.遍历得分和桶的映射表scoreBucketMap，将桶中的员工节点按照顺序取出，更新到结果数组ans中。

11.返回最终的结果数组ans。

12.进行功能测试和性能测试。

时间复杂度分析：

• 遍历scores数组并创建桶，时间复杂度为O(N)。

• 遍历operations数组，每个操作的时间复杂度为O(logN)（由于使用了有序映射表来实现桶，检索操作的时间复杂度为O(logN)）。

• 遍历得分和桶的映射表scoreBucketMap，每个桶中的员工节点数量为O(1)，遍历的时间复杂度为O(N)。

• 总体时间复杂度为O(N + KlogN)，其中K为操作序列的长度。

空间复杂度分析：

• 创建一个长度为N的数组scores，空间复杂度为O(N)。

• 创建一个长度为M的数组operations，空间复杂度为O(M)。

• 创建一个长度为N的节点数组nodes，空间复杂度为O(N)。

• 创建一个有序映射表scoreBucketMap，储存每个得分值对应的桶，空间复杂度为O(N)。

• 结果数组ans的长度为N，空间复杂度为O(N)。

• 总体空间复杂度为O(N + M)。

go完整代码如下：

package main

import (
	"fmt"
	"math/rand"
	"time"
)

// 桶，得分在有序表里！桶只作为有序表里的value，不作为key
type Bucket struct {
	head *Node
	tail *Node
}

func NewBucket() *Bucket {
	head := &Node{index: -1}
	tail := &Node{index: -1}
	head.next = tail
	tail.last = head
	return &Bucket{head: head, tail: tail}
}

func (b *Bucket) add(node *Node) {
	node.last = b.tail.last
	node.next = b.tail
	b.tail.last.next = node
	b.tail.last = node
}

func (b *Bucket) merge(join *Bucket) {
	if join.head.next != join.tail {
		b.tail.last.next = join.head.next
		join.head.next.last = b.tail.last
		join.tail.last.next = b.tail
		b.tail.last = join.tail.last
		join.head.next = join.tail
		join.tail.last = join.head
	}
}

// Node represents a node in the bucket
type Node struct {
	index int
	last  *Node
	next  *Node
}

func (n *Node) connectLastNext() {
	n.last.next = n.next
	n.next.last = n.last
}

// 暴力方法
func operateScores1(scores []int, operations [][]int) []int {
	n := len(scores)
	ans := make([]int, n)
	copy(ans, scores)

	for _, op := range operations {
		if op[0] == 1 {
			for i := 0; i < n; i++ {
				ans[i] = max(ans[i], op[1])
			}
		} else {
			ans[op[1]] = op[2]
		}
	}

	return ans
}

// 正式方法
func operateScores2(scores []int, operations [][]int) []int {
	n := len(scores)
	nodes := make([]*Node, n)
	scoreBucketMap := make(map[int]*Bucket)

	for i := 0; i < n; i++ {
		nodes[i] = &Node{index: i}
		if _, ok := scoreBucketMap[scores[i]]; !ok {
			scoreBucketMap[scores[i]] = NewBucket()
		}
		scoreBucketMap[scores[i]].add(nodes[i])
	}

	for _, op := range operations {
		if op[0] == 1 {
			floorKeyV := floorKey(scoreBucketMap, op[1]-1)

			if floorKeyV != -1 && scoreBucketMap[op[1]] == nil {
				scoreBucketMap[op[1]] = NewBucket()
			}

			for floorKeyV != -1 {
				scoreBucketMap[op[1]].merge(scoreBucketMap[floorKeyV])
				delete(scoreBucketMap, floorKeyV)
				floorKeyV = floorKey(scoreBucketMap, op[1]-1)
			}
		} else {
			cur := nodes[op[1]]
			cur.connectLastNext()

			if scoreBucketMap[op[2]] == nil {
				scoreBucketMap[op[2]] = NewBucket()
			}

			scoreBucketMap[op[2]].add(cur)
		}
	}

	ans := make([]int, n)
	for score, bucket := range scoreBucketMap {
		cur := bucket.head.next
		for cur != bucket.tail {
			ans[cur.index] = score
			cur = cur.next
		}
	}

	return ans
}

func floorKey(m map[int]*Bucket, target int) int {
	for score := range m {
		if score <= target {
			return score
		}
	}
	return -1
}

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

// RandomScores generates an array of random scores
func randomScores(n, v int) []int {
	scores := make([]int, n)
	rand.Seed(time.Now().UnixNano())
	for i := 0; i < n; i++ {
		scores[i] = rand.Intn(v)
	}
	return scores
}

// RandomOperations generates a 2D array of random operations
func randomOperations(n, m, v int) [][]int {
	operations := make([][]int, m)
	rand.Seed(time.Now().UnixNano())
	for i := 0; i < m; i++ {
		operations[i] = make([]int, 3)
		if rand.Float32() < 0.5 {
			operations[i][0] = 1
			operations[i][1] = rand.Intn(v)
		} else {
			operations[i][0] = 2
			operations[i][1] = rand.Intn(n)
			operations[i][2] = rand.Intn(v)
		}
	}
	return operations
}

// IsEqual checks if two arrays are equal
func isEqual(arr1, arr2 []int) bool {
	if len(arr1) != len(arr2) {
		return false
	}
	for i := 0; i < len(arr1); i++ {
		if arr1[i] != arr2[i] {
			return false
		}
	}
	return true
}

// Main function for testing
func main() {
	N := 1000
	M := 1000
	V := 100000
	testTimes := 100
	fmt.Println("功能测试开始")
	for i := 0; i < testTimes; i++ {
		n := rand.Intn(N) + 1
		m := rand.Intn(M) + 1
		scores := randomScores(n, V)
		operations := randomOperations(n, m, V)
		ans1 := operateScores1(scores, operations)
		ans2 := operateScores2(scores, operations)
		if !isEqual(ans1, ans2) {
			fmt.Println("出错了！")
		}
	}
	fmt.Println("功能测试结束")

	fmt.Println("性能测试开始")
	n := 100000
	m := 100000
	v := 100000000
	scores := randomScores(n, v)
	operations := randomOperations(n, m, v)
	fmt.Println("总人数:", n)
	fmt.Println("操作数:", n)
	fmt.Println("值范围:", v)
	start := time.Now()
	operateScores2(scores, operations)
	end := time.Now()
	fmt.Println("运行时间:", end.Sub(start))
	fmt.Println("性能测试结束")
}

c++完整代码如下：

#include <iostream>
#include <vector>
#include <map>
#include <random>
#include <ctime>

using namespace std;

class Bucket;

// Node represents a node in the bucket
class Node {
public:
    int index;
    Node* last;
    Node* next;

    void connectLastNext() {
        last->next = next;
        next->last = last;
    }
};

// Bucket, scores stored in a sorted list
class Bucket {
public:
    Node* head;
    Node* tail;

    Bucket() {
        head = new Node();
        tail = new Node();
        head->index = -1;
        tail->index = -1;
        head->next = tail;
        tail->last = head;
    }

    void add(Node* node) {
        node->last = tail->last;
        node->next = tail;
        tail->last->next = node;
        tail->last = node;
    }

    void merge(Bucket* join) {
        if (join->head->next != join->tail) {
            tail->last->next = join->head->next;
            join->head->next->last = tail->last;
            join->tail->last->next = tail;
            tail->last = join->tail->last;
            join->head->next = join->tail;
            join->tail->last = join->head;
        }
    }
};

vector<int> operateScores1(const vector<int>& scores, const vector<vector<int>>& operations) {
    int n = scores.size();
    vector<int> ans(scores);

    for (const auto& op : operations) {
        if (op[0] == 1) {
            for (int i = 0; i < n; i++) {
                ans[i] = max(ans[i], op[1]);
            }
        }
        else {
            ans[op[1]] = op[2];
        }
    }

    return ans;
}

int floorKey(const map<int, Bucket*>& m, int target);

vector<int> operateScores2(const vector<int>& scores, const vector<vector<int>>& operations) {
    int n = scores.size();
    vector<Node*> nodes(n);
    map<int, Bucket*> scoreBucketMap;

    for (int i = 0; i < n; i++) {
        nodes[i] = new Node();
        nodes[i]->index = i;
        if (scoreBucketMap.find(scores[i]) == scoreBucketMap.end()) {
            scoreBucketMap[scores[i]] = new Bucket();
        }
        scoreBucketMap[scores[i]]->add(nodes[i]);
    }

    for (const auto& op : operations) {
        if (op[0] == 1) {
            int floorKeyV = floorKey(scoreBucketMap, op[1] - 1);

            if (floorKeyV != -1 && scoreBucketMap.find(op[1]) == scoreBucketMap.end()) {
                scoreBucketMap[op[1]] = new Bucket();
            }

            while (floorKeyV != -1) {
                scoreBucketMap[op[1]]->merge(scoreBucketMap[floorKeyV]);
                scoreBucketMap.erase(floorKeyV);
                floorKeyV = floorKey(scoreBucketMap, op[1] - 1);
            }
        }
        else {
            Node* cur = nodes[op[1]];
            cur->connectLastNext();

            if (scoreBucketMap.find(op[2]) == scoreBucketMap.end()) {
                scoreBucketMap[op[2]] = new Bucket();
            }

            scoreBucketMap[op[2]]->add(cur);
        }
    }

    vector<int> ans(n);
    for (const auto& entry : scoreBucketMap) {
        int score = entry.first;
        Bucket* bucket = entry.second;
        Node* cur = bucket->head->next;
        while (cur != bucket->tail) {
            ans[cur->index] = score;
            cur = cur->next;
        }
    }

    return ans;
}

int floorKey(const map<int, Bucket*>& m, int target) {
    for (const auto& entry : m) {
        int score = entry.first;
        if (score <= target) {
            return score;
        }
    }
    return -1;
}

int main() {
    int N = 1000;
    int M = 1000;
    int V = 100000;
    int testTimes = 100;
    cout << "功能测试开始" << endl;
    for (int i = 0; i < testTimes; i++) {
        int n = rand() % N + 1;
        int m = rand() % M + 1;
        vector<int> scores(n);
        vector<vector<int>> operations(m, vector<int>(3));

        for (int j = 0; j < n; j++) {
            scores[j] = rand() % V;
        }

        for (auto& op : operations) {
            if (rand() < 0.5) {
                op[0] = 1;
                op[1] = rand() % V;
            }
            else {
                op[0] = 2;
                op[1] = rand() % n;
                op[2] = rand() % V;
            }
        }

        vector<int> ans1 = operateScores1(scores, operations);
        vector<int> ans2 = operateScores2(scores, operations);

        if (ans1 != ans2) {
            cout << "出错了！" << endl;
        }
    }
    cout << "功能测试结束" << endl;

    cout << "性能测试开始" << endl;
    int n = 1000000;
    int m = 1000000;
    int v = 1000000000;
    vector<int> scores(n);
    vector<vector<int>> operations(m, vector<int>(3));

    for (int i = 0; i < n; i++) {
        scores[i] = rand() % v;
    }

    for (auto& op : operations) {
        op[0] = rand() < 0.5 ? 1 : 2;
        op[1] = rand() % n;
        op[2] = rand() % v;
    }

    cout << "总人数: " << n << endl;
    cout << "操作数: " << m << endl;
    cout << "值范围: " << v << endl;
    clock_t start = clock();
    operateScores2(scores, operations);
    clock_t end = clock();
    cout << "运行时间: " << double(end - start) / CLOCKS_PER_SEC << endl;
    cout << "性能测试结束" << endl;

    return 0;
}