astro a50 1 2 3

Using formula (n-1) 3=N3-3n2+ 3n-1 Set S3 =13+ 23+ 33+ 43+... + N3 And S2 =12+ 22+ 32+ 42+... + N2 And S1 = 1 + 2 + 3 + 4 +... + n D: S3-3S2 + 3s1-n = (1-

Opencv experiences (1) The second chapter of learning opencv mainly introduces some common and interesting functions and data types, so that students at the beginning are more interested in image processing, although I do not understand the internal experiment of the function and the meaning of some defined constants, I am still very happy after learning Chapter 2. At least I know some basics of image proce

Starting 3 threads, thread 1 printing 1 to 5, thread 2 printing 5 to 10, thread 3 printing 11 to 15, then thread 1 printing 16 to 20, and so on ... Print until 30 public class Mainthread {private static int num;//current reco

Problem description: there are now n ordered arrays in M groups, such as {1, 2, 3, 4}, {2, 3, 6}, {1, 3, 5, 7 }, select the data smaller than K in these arrays and return this value. Id

#!/usr/bin/env python# Coding:utf-8Import Redef Dealwith (Express): Express.replace ('+-','-') Express.replace ('--','+') returnexpressdef Col_suanshu (exp):if '/' inchexp:a,b= Exp.split ('/') returnStrfloat(a)/float(b))if '*' inchexp:a,b= Exp.split ('*') returnStrfloat(a) *float(b) def get_no_barcate (Express): Express=express.strip ('()') Print ('>>>', Express) whileTrue:ret= Re.search ("-?\d+\.? \d*[*/]-?\d+\.? \d*", Express)ifRet:res=Col_suanshu (Ret.group ()) Express= Ex

protected] "0 "; Cale. A1 = 0; Cale. A2 = 0; Cale. Op = 0; } -(Ibaction) but1 :( ID) sender { If (Cale. Op! = 0) { Cale. A2 = Cale. A2 * 10 + 1; Self. Label. Text = [nsstring stringwithformat: @ "% F", Cale. A2]; } Else { Cale. A1 = Cale. A1 * 10 + 1; Self. Label. Text = [nsstring stringwithformat: @ "% F", Cale. A1]; } } -(Ibaction) but2 :( ID) sender { If (Cale. Op! = 0) { Cale. A2 = Cale. A2 * 10

def groupBy (FN): def Go (LST): = {} for in lst: ifelse m.update ({fn (v): [v]}) #如果存在dict, append to the corresponding key, or none if it does not exist, then update a new key to return m return = GroupBy (lambdais 1) grpby ([1, 2, 3]) The Python implements the GroupBy function. Grpby = GroupBy (

using System; using System.Collections.Generic; using System.Text; namespace ExSum { 　　class Sum 　　{ 　　　　public long sum(int num) 　　　　{ 　　　　　　long sum = 0; 　　　　　　for (int i = 1; i 　　　　　　{ 　　　　　　　　long f = 1; 　　　　　　　　//求i的i次方 　　　　　　　　for (int j = 1; j 　　　　　　　　{ 　　　　　　　　　　f *= i; 　　　　　　　　} 　　　　　　　　sum += f; 　　　　　　} 　　　　　　return sum; 　　　　} 　　　　static void Main(str

C language computing 1/1-1/2 + 1/3-1/4 + 1/5-... + 1/99-1