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I Need A HELP FOR C++ ASSIGNMENT ~ASAP?

4
2006-07-30 04:33:19, Category: Programming & Design
i have problem with my assignment!! the question is " write a c++ program that, given an even integer greater than two, (but no greater than one thounsand), produce as output every pair of prime number that sum to it." eg: input a number is 12 output is 5 7 eg: 38 output: 7 31 19 19 my c++ code is: //countfactors.cpp //This program will determine the number of factors of a given number //And wiil produce every pair of prime number that sum to the given number #include #include using namespace std; int main() { int cout=0; //the number of factors //get input cout << " Please enter a positive even interger: "; cin >> number; for(int i=2; i<=1000; i++) { if (number%1==0) { cout ++; }//end if }//end loop cout << "There are " << cout << " factors" << endl; if(cout==2) { cout << "The number is prime" << endl; }//end if system("PAUSE"); return 0; }//end main can u check my code?? i need to give it to teacher on tuesday 1 August 2007 , so can u reply to me today.. thanks I Need someone to correct my C++. I just doing the basic C++ the beginner course~ Orkut Community?? what is the web address?? i am using DEV-C++ to write the code

Answers

  1. Shamiul_islam

    On 2006-07-30 10:15:50


    main() {int a,b,c,first,second,given_n,num; float check; top: clrscr(); printf("Enter number smaller than 1000 & greater than two :"); scanf("%d",&given_n); if(given_n>1000&&given_=<2)goto top; for(first=1;first

  2. Scott c

    On 2006-07-30 04:37:03


    are you looking for us to do your work ???

  3. 3dillusion

    On 2006-07-30 07:32:42


    Let me try! Modify the input code first. Your code takes an Input, it doesn't make sure whether the input is actually +ve even integer less than 1000. That will cause problem in the codes below. here it is: -------------------- int number=0; // U Have not declared number as int , no can do while (number<=2 || number >=1000) { cout << "\nPlease enter a positive even interger <1000 : "; cin>>number; } -------------------- now the code to count factors. declare int count , not int cout . cout is part of c++ iostream library. loop for n / 2 times. Obviously a number greater than n / 2 can't be factor of n , can it ? NO. So save time and make the loop i=2 to n / 2 . code: ------------------------ int count=0; for(int i=2; i<=(number/2); i++) { if (number % i == 0) count ++; // A single statement just after if does not require braces }//end loop ------------------------ Check prime or not! A number is always divisible by 1 and itself. If they are the only 2 factors the its a prime. So checking from 2 to n/2 , if the number encounters no factors then its a prime. count=0 is the condition. Your code checks for 2 to <= n , so if u want to keep that [ i wud recommend not to ] then check for count = 1, as finally i becomes = n , and n % n = 0 ! And that must be the only factor [ seeing that you started from 2 , 1 is not checked at all] . code: ------------------------ cout << "There are " << count << " factors" << endl; if(count == 0) cout << "The number is prime" << endl; ------------------------ Your code till this only checks whether number is prime and its no. of factors. The rest of the dirty works still remain. U still have to find pairs of prime numbers whose sum yield the Input number. Try urself and put the code on or mail me. I shall check the code and advise you likewise. If you put the code here as a new question email me the topic name ok ? It wud be better if u put it with same topic. ------=-=-=-=-=-=------- To pause the program use getch() ; and b4 include conio.h getch() is a function which holds the program till there is a niput from keyboard. effectivly , unless user hits a [any] key the program cannot start execution of next lines of code. code: ------------------------ cout<<" Hit a key to end execution "; getch(); return 0; } ------------------------ Orkut community @ http://www.orkut.com/Community.aspx?cmm=591 http://www.orkut.com/Community.aspx?cmm=38750

  4. Eby M

    On 2006-07-30 04:39:06


    join orkut C++ community they will definitly help u