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This article mainly introduces "how to use the web partition algorithm". In daily operation, I believe many people have doubts about how to use the web partition algorithm. I have consulted all kinds of materials and sorted out simple and easy operation methods. I hope to help you answer the doubts about "how to use the web partition algorithm"! Next, please follow the small series to learn together!

I. Basic concepts

Divide and conquer is an important algorithm in computer science. The literal interpretation is divide and conquer, which is to divide a complex problem into two or more identical or similar subproblems, and then divide the subproblems into smaller subproblems…until the final subproblems can be solved simply and directly, and the solution of the original problem is the combination of the solutions of the subproblems. This technique is the basis of many efficient algorithms, such as sorting algorithms (fast sort, merge sort), Fourier transforms (fast Fourier transforms)…

The computational time required for any computer-solvable problem depends on its size. The smaller the size of the problem, the easier it is to solve directly and the less computational time it takes to solve it. For example, for the sorting problem of n elements, when n=1, no computation is required. When n=2, only one comparison is needed to arrange the order. When n=3, only three comparisons can be made. When n is large, the problem is less tractable. It is sometimes quite difficult to solve a problem of a large scale directly.

II. Basic Ideas and Strategies

Divide and conquer is designed to divide a large problem that is difficult to solve directly into smaller problems of the same size, so that they can be broken down one by one.

The divide-and-conquer strategy is: for a problem of size n, if the problem can be easily solved (for example, the size n is small), solve it directly; otherwise, decompose it into k smaller subproblems, which are independent of each other and have the same form as the original problem, recursively solve these subproblems, and then combine the solutions of each subproblem to obtain the solution of the original problem. This algorithm design strategy is called divide and conquer.

If the original problem can be divided into k subproblems, 1 high){ return -1; } while(low key){ high = middle -1; } else if(arr[middle]

< key){ low = middle + 1; } else { return middle; } } return -1; } 三、归并排序 归并排序（MERGE-SORT）是利用归并的思想实现的排序方法，该算法采用经典的分治（divide-and-conquer）策略（分治法将问题分(divide)成一些小的问题然后递归求解，而治(conquer)的阶段则将分的阶段得到的各答案"修补"在一起，即分而治之)。 第一, 分解: 把待排序的 n 个元素的序列分解成两个子序列, 每个子序列包括 n/2 个元素. 第二, 治理: 对每个子序列分别调用归并排序MergeSort, 进行递归操作 第三, 合并: 合并两个排好序的子序列,生成排序结果.

public static int[] sort(int[] a,int low,int high){ int mid = (low+high)/2; if(low

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