84 lines
2.5 KiB
C++
84 lines
2.5 KiB
C++
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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* Champlain College SDEV-340-81
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*
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* C++ Week 5: Assignment (second semester) - Recursion Continued (2020/06/20)
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*
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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*
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* Working with recursion
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* Recursion - Chapter 14 (Page 947)
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* Programming Challenge (4. Recursive Array Sum) Sum numbers recursively
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*
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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*
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* Written by Llewellyn van der Merwe <llewellyn.vandermerw@mymail.champlain.edu>, June 2020
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* Copyright (C) 2020. All Rights Reserved
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* License GNU/GPL Version 2 or later - http://www.gnu.org/licenses/gpl-2.0.html
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*
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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#include <iostream>
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#include <vector>
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#include <sstream>
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using namespace std;
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int sumRecursive(int n, int array[]);
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int main() {
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// string to get user input
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string user_input;
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// now ask for the integers
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cout << "Enter space separated list of integers you would like to sum:" << endl;
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// get the user input of integer
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getline(cin, user_input);
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// convert to string stream
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stringstream user_input_stream(user_input);
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// the vector array of integers
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vector<int>array;
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int number;
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while(user_input_stream >> number){
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// add the number
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array.push_back(number);
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// skip empty space
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if(user_input_stream.peek() == ' ') user_input_stream.ignore();
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}
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// get size
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int SIZE = array.size();
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// start array of int
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int arr[SIZE];
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// little counter for +
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number = 0;
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// print out the numbers entered and build array
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for(int val : array) {
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// add to array
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arr[number] = val;
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// increment the number
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number++;
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// print out the value
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cout << val;
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// just add for the first numbers
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if(number < SIZE) {
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cout << " + ";
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}
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}
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// give back answer
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cout << " = " << sumRecursive(SIZE, arr) << endl;
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}
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// multiply numbers recursively
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int sumRecursive(int n, int array[]) {
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// lower to previous index
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--n;
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// get current value
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int number = array[n];
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// are we at the first element
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if (n == 0) {
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// return first "last" number
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return number;
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} else {
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// recursive call
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return number + sumRecursive(n , array);
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}
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}
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