Initialization and passing an array - c++

Question

I am trying to create a program that will draw using a single dimensional array however I am having a hard time initializing the array using only one cin statement. A sample input that the user in supposed to look like
1<space>2<space>34<space>3<space>2<space>1<space>0<space>10
#include<iostream>
using namespace std;
/*---------------------------------------------------------------------------------------
Prototypes
These are the prototype function(s) that will be used to to draw the row and columns
---------------------------------------------------------------------------------------*/
void draw(int nums);
//---------------------------------------------------------------------------------------
int main(){
const int MAX = 100;
int chart[MAX];
int nums;
cout << "Enter numbers for the chart" << endl;
cin >> nums;
draw(nums);
return 0;
}
void draw(int nums) {
cout << endl;
int row;
for (row = 0; row < nums; ++row) {
cout << "*" << endl;
}
}
How would I initialize the array with the sample input given and then pass it to a function to be used to draw

Answer 1

Here's a simple (perhaps unsafe but then again don't use std::cin for safety) implementation that seems to work for reading in the numbers:
#include <iostream>
#include <list>
#include <sstream>
int main()
{
std::cout << "Input numbers: ";
// get input line
std::string input;
std::getline(std::cin, input);
std::stringstream ss(input);
// read numbers
std::list<int> numbers;
while(ss) {
int number;
ss >> number;
ss.ignore();
numbers.push_back(number);
}
// display input
for(const auto number: numbers) {
std::cout << number << std::endl;
}
return 0;
}
And here's a sample run:
$ ./a.out
Input numbers: 1 2 3 4
1
2
3
4

Answer 2

I think you need a parse to decode the input. something like following:
void parse(const std::string& input, int output[], int MaxNum)
{
// parse the integer from the string to output.
}
int main(){
......
std::string input;
cout << "Enter numbers for the chart" << endl;
cin >> input;
parse(input, chart, MAX);
......
}

Answer 3

Here is a version of a program that lets you input a series of numbers with only one cin line with the help of stringstream, but the only difference is that it stores the input in a vector. It then draws a histogram chart based on the input.
Just press the <ENTER> key twice to let the program know that you are done with the inputting of the numbers.
#include <iostream>
#include <iterator>
#include <vector>
#include <algorithm>
#include <sstream>
using namespace std;
vector<int> Vector;
string line;
void drawchart(int max);
int main() {
cout<<"Chart drawing program ( Histogram) \n";
cout<<"Enter a series of numbers. \n";
cout<<"Seperate with a space, press <ENTER> TWICE to end input \n";
cout<<" (e.g 2 3 4 5 6) > ";
if(!getline(cin, line)) return 1;
istringstream iss(line);
copy( istream_iterator<int>(iss), istream_iterator<int>(), back_inserter(Vector));
copy(Vector.begin(), Vector.end(), ostream_iterator<int>(cout, ", "));
cout<<"\nDrawing chart.. \n\n";
drawchart( Vector.size() );
cout<<"Press ANY key to close.\n\n";
cin.ignore();cin.get();
return 0;
}
// draws a chart or hjistogram
void drawchart(int max){
for( int i = 0; i < max ; i++){
for(int j = 0; j < Vector[i]; j++) cout << "*";
cout << endl;
}
}