Not adding right

[tlephin]

Sorry that this is my second post tonight. But I finally got this program working but its not adding correctly. Instead of 2 + 2 = 4 it equals 8.

The program is supposed to be able to take a list of up to 100 integers and output the sum.

#include <iostream>
#include <cmath>
using namespace std;
const int NUM = 100;

int main(){

	// init variable
	int sum = 0;

	// init array
	int arr[NUM];
	for (int i = 0; i < NUM; i++)
		arr[i] = 0;

	// Welcome and Prompt
	cout << "Welcome to the line adder\n"
		<< "Please enter the numbers you wish to be added" << endl;

	// getting the numbers into the array
	for ( int i = 0; i < NUM; i++){
		 if (cin.peek() != '\n'){
			 cin >> arr[i];
		 
			 for (int j = 0; j < arr[i]; j++){
				sum = sum + arr[i];	
			 }
		 }
		 else{
			break;
		 }
	}
	cout << sum;

		// pause and exit
		getchar();
		getchar();
		return 0;
}

[TheKingOfTyrants]

Your problem is that you're double, triple, quadruple... counting becase of your for-loop on line 25. You only want to add the number last inputted to sum, but instead you loop through your whole arr again.

[tlephin]

I thought it might have something to do with that. However, if i place that loop anywhere else arr[i] isn't identified. So i have no idea where to put it. Should i make another array and copy arrr[i] into it?

[TheKingOfTyrants]

You do not need a loop. You only need to add a value to sum every time you get a value from the user. You only need the statement in the loop, not the actual loop surrounding it.

[tlephin]

OH! That makes so much sense!
Both problems you helped me resolve were such a quick fix.
Thank you again!