Creation of sequence 1, 12, 123,

[PainterGuy]

Hello everyone,

I was working to create a program to list the sequence:
1
12
123
1234
12345
...

The user will decides how many terms of sequence are displayed. For example the terms, n, given above are five. Will you help me please? I think I need to use the FOR loop here. Given below are some random steps I put down. My math is weak.

second term - first term = 11
third term - second term = 111
fourth term - third term = 1111
...

The code written below is wrong. I have included it so that you can help.

#include <iostream>
#include <cstdlib>
#include <cmath>

using namespace std;

int main()

{
 	
 	int n, i;
 	
 	cout << "How many terms are required?: ";
 	cin >> n;
 	
 	cout << " " << endl;
 	
 	for ( i=1; i<=n; i =i+(pow(10,i)))
 	
 	{
	 	
	 	cout << i << endl;
	 	
    }
		
}

Cheers

 

[chiro]

Hello everyone,

I was working to create a program to list the sequence:
1
12
123
1234
12345
...

The user will decides how many terms of sequence are displayed. For example the terms, n, given above are five. Will you help me please? I think I need to use the FOR loop here. Given below are some random steps I put down. My math is weak.

second term - first term = 11
third term - second term = 111
fourth term - third term = 1111
...

The code written below is wrong. I have included it so that you can help.

#include <iostream>
#include <cstdlib>
#include <cmath>

using namespace std;

int main()

{
 	
 	int n, i;
 	
 	cout << "How many terms are required?: ";
 	cin >> n;
 	
 	cout << " " << endl;
 	
 	for ( i=1; i<=n; i =i+(pow(10,i)))
 	
 	{
	 	
	 	cout << i << endl;
	 	
    }
		
}

Cheers

Hey painterguy. Just a question: Why do you have i=i + (pow(10,i))? If you want to print the terms 1234... just increment that loop by 1 (ie i=i+1 or i++).

Also if you want to do that repeat like you have done like print

1
12
123
1234

for n = 4 (or any n) you need another loop. So in your outer loop you will go from 1 to n (call it x) and in your inner loop you will go from 1 to x.

Just out curiosity so I know your thought process, why did you use the pow statement? I'm not criticizing, I'm just curious about your thought process.

 

[rcgldr]

Your method will work, but you need another variable to hold the intermediate sum (1, 11, 111, 1111, ...), and yet another to hold the total sum, and only use i as an incremental number. Also you need to start at 0, not 1 (pow(10,0) == 1), so that would be for(i=0; i<n; i++) ... You could use j to hold the intermediate sum, and k to hold the total sum.

Note, a simpler alternative method would be to repeatedly multiply a number by 10 and add i in each loop.

 

[PainterGuy]

Hello chiro, rcgldr,

I am very much thankful to you both for your replies. The problem was solved but I have been little lazy in extending my thanks. :) Actually I was away.

Cheers