Help with program

[Arnau]

I'm new programming and I need to build a program that tells you when you input an unlimited number of numbers, how many and which numbers finish in the same three digits of the first input number.

I don't know how to put an unlimited number of inputs and also don't know how to do the rest.

I have started CS major and have to deliver this tomorrow and don't know how. I would appreciate any help. Thanks.

[shadowCODE]

You will need to use a loop with a sentinel value. http://en.wikipedia.org/wiki/Sentinel_value

A counter that will count the number of inputs during the live span of the loop.

a variable to hold the first input.

a dynamically allocated array that will hold the numbers that have the same 3 last digits as the first input.

The number of numbers that have the same last 3 digits will be the size of the array.

implement this and let us know what you have done.

[Arnau]

Thanks for your quick reply, well the fact is that I have had only two theory sessions and in theory and to explain things clearly I'll say that I have no fucking idea of what I'm doing. Other students have programmed a lot before but I haven't, and the teacher assumes that we already know things that I don't. So I won't be able to solve that problem with your indications at the moment...
What I really need to see are examples of basic programs so I can see the syntaxis and how c++ works.
Do you know any website or book I can read that has that ?

Thank you very much.

[Victor89]

One idea will be to use an array to store the numbers.
We define the array A[100] which means we can store 100 numbers, in this array.
The variable n will be the number of the numbers.

#include <iostream>
#include <conio.h>

using namespace std;

int main()
{
	int A[100], i, n;
	cout << "How many numbers do you want to input?\n";
	cin >> n; // reading the number of the numbers

	for(i=0; i<n; i++)
	{
	cin >> A[i]; //reading the array
	}

	cout << "The numbers are:\n";
	for(i=0; i<n; i++)
	{
	cout << A[i] << " "; //displaying the numbers you entered

	}
	
	_getch();
}

Now if you want to get the last 3 digits of the number you should use the modulo operator. Modulo will get the remainder of the division.

Number % 3 // will get the last 3 digits of the number

This can be one idea. Good luck!

[shadowCODE]

Using an array[100] limits the input to 100 input. The question explicitly specifies unlimited input.

This program will solve your problem and hope you understand it.

about, C++ books and references, i tought my self with Prentice Hall, C++ How to Program (8th Edition) http://downloadfreecomputerbooks.blogspot.com/2012/08/c-how-to-program-8th-edition.html

#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
using namespace std;

void getLastThree(vector<int> &, int ); //as the name implies

int main()
{
    int first;  //first input number: reference
    int number; //consegative numbers
    int count = 0;  //number of inputs

    vector<int> lastThree;  //last three digits of reference input
    vector<int> newLastThree;   //last three digits of consegative input
    vector<int> matchLastThree; //numbers with matches

    ostream_iterator<int> output(cout,"\n");    //ouput
    do
    {
        cout<<"Enter number(>= 100): "; //at least 3 digits
        cin>>first;
        getLastThree(lastThree,first);
    }while(first < 100);        //loop until the first digit is at least 3 digits

    do
    {
        cout<<"Enter number( 0 to end):  ";
        cin>>number;
        if(number > 100)
        {
            getLastThree(newLastThree,number);
        }
        if(lastThree == newLastThree)
            matchLastThree.push_back(number);   //add the number to the matches vector
        newLastThree.erase(newLastThree.begin(),newLastThree.end());    //reset
        ++count;
    }while(number != 0);

    cout<<"\nThe total number of numbers entered is "<<count<<endl;
    cout<<"The number of last three digit matches with the first is "<<matchLastThree.size()<<endl;
    cout<<"The matches are :\n\n";
    copy(matchLastThree.begin(),matchLastThree.end(),output);   //output the vector
}
void getLastThree(vector<int> &vec, int number)
{
    for(int i = 0; i < 3; i++)
    {
        int r = number%10;
        vec.push_back(r);
        number /= 10;
    }
}

[Arnau]

thanks to all of you !! I solved the problem :)