at t tn

Proof: Using formula (n-1) 3 = N3-3N2 +3n-1 S3 = +23 +33 +43 +...+n3 S2 = +22 +32 +42 +...+n2 S1 = 1 +2 +3 +4+...+n = S3-3s2+3s1-n = (1-1) 3 + (2-1) (3-1) 3 + (4-1) 3 + ... + (n-1) 3 = S3-n3 = 3S2 = 3s1+n3-n and s1= N (

//你知道为什么快速排序的时间复杂度是nlgn吗? We look at the array as a complete binary number and put it in a small heap,The ordering of each node requires O (h), which is H, H is the height of the two fork tree of the fully corresponding node,n is the total number of nodes, the row of a node needs O (h) times, then row n nodes?and 2^h=n-1 (full binary tree nature);->H=LOG2 (

Note:Char Tempa [20] = {'/0'}; the actual length of Tempa is 0. Char * A = {'/0'}; the length of A is also 0, but after such declaration, you cannot assign values one by one as * (a + I ). String = character array + '/0' ========================================================== = # Include # Include # Include # Include Using namespace STD;# Define n 3000Int res [N]; /****** Function:* Parameters:* A: Mul

Given an array a [n], we want to construct array B [N], where B [I] = A [0] * A [1] *... * A [N-1]/A [I].The construction process must meet the following requirements:1. Division is not used;2,O (1)Spatial complexity andO (N)Time complexity;3. In addition to traversing the counters used by a [

Original title: http://acm.hdu.edu.cn/showproblem.php?pid=1081Main topic:For a square of a given edge length, select a rectangle so that it contains the largest value of all the elements.As we all know (a+b) ^2, the optimization here is using this principle to do optimization, our DP value is the value of the rectangular area of our former I row J column.The values of any rectangular area can also be solved by this expansion, so we can violently enumerate each of the cases in the upper-left corn

We are here to introduce some about n! of the nature.in counting problems, it is often necessary to useN!. It is necessary to understandN! In themod punder some of the properties. Now let's assumePis the prime number,N! =ape(Acannot bep divisible ) and try to solve E and a mod p ( To figure this out can be a good reduction in the data of the combined number of modules) e is

Too lazy to translate, to the effect: Top N and SET rowcount n are the same fast when there is a suitable index. But for an unordered heap, top n is faster. The principle of looking at English to go. Q. Is using the TOP N clause faster than using SET ROWCOUNT N to return a s

To find the factorial of n#include #include int Main (){ int n = 0; int sum = 1;scanf ( "%d", n); while (n)//n, if zero, does not enter the loop body, the sum initial value of the output is 1{Sum *=n;

Use the n tool to easily manage the Node. js version and the n tool node. js version. Preface I believe that for learning Node. as all js colleagues know, the Node version is updated quickly. Currently, the latest stable version has been updated to v7.6.0, while the production environment generally uses the LTS (Long-term Support) version, the latest version is v6.10.0. Local LTS download:Click here The new

divisible by 4.2. What is the effect of byte alignment?Byte alignment is not only convenient for fast CPU access, but also a reasonable use of byte alignment can effectively save storage space.For a 32-bit machine, 4-byte alignment can increase the speed of the CPU access, such as a long variable, if the 4-byte boundary is stored, then the CPU reads two times, so the efficiency is low. However, using a 1-byte or 2-byte alignment in a 32-bit machine can cause variable access speed to be reduced.