Sample Paypal Integration Code

- (void)sendPayPalRequestPOST{

NSString *parameterString = [NSString stringWithFormat:@"USER=usernamehere"

"&PWD=passwordhere"

"&SIGNATURE=signaturekeyhere"

"&METHOD=DoDirectPayment"

"&CREDITCARDTYPE=%@"

"&ACCT=%@"

"&EXPDATE=%@"

"&CVV2=256"

"&AMT=%@"

"&FIRSTNAME=%@"

"&LASTNAME=%@"

"&STREET=%@"

"&CITY=%@"

"&STATE=%@"

"&COUNTRY=%@"

"&ZIP=%@"

"&COUNTRYCODE=US"

"&PAYMENTACTION=Sale"

"&VERSION=2.3",

txtCreditCardType.text,txtAccountNumber.text,txtExpireDate.text,txtTotalAmount.text,txtFirstName.text,txtLastName.text,txtStreet.text,txtCity.text,txtState.text,txtCountry.text,txtZip.text];

NSURL *url = [NSURL URLWithString:@"https://api-3t.sandbox.paypal.com/nvp"];

NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];

NSString *msgLength = [NSString stringWithFormat:@"%d", [parameterString length]];

[theRequest addValue: msgLength forHTTPHeaderField:@"Content-Length"];

[theRequest setHTTPMethod:@"POST"];

[theRequest setHTTPBody: [parameterString dataUsingEncoding:NSUTF8StringEncoding]];

NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];

if(theConnection){

webData = [[NSMutableData data] retain];

}else{

}

}

How to create a multimonitor setup ?

Article found in CHIP megazine Nov 2008 page no: 114

Sequence & Series Formulas

Arithmatic Progression

a,a+d,a+2d...., a+nd

• nth term of arithmatic progression
  

Tn = a + (n-1) d

• Sum of n - terms of arithmatic progression
  

Sn= (n/2) [ 2a + (n - 1) d]

• if a,b and c are in arithmatic progression then b = (a + c)/2.

Geomatric Progression

a,ar,ar^2,..., ar^n

• nth term of geomatric progression is given by Tn = a r^(n-1).
• Sum of the first n terms of geomatric progression is given by;

Sn = a [ (1 - r^n) / (1 - r) ] , for r<1>

Sn = a [ (r^n - 1)/ (r - 1) ], for r>1

• if three quantities a,b and c are in GM then b = Sqrt(ac);
• Infinite Geomatric Series

when |r|<1   

S* = a / (1 - r);

when |r|>1 then 

S*= Infinity;

Harmonic Mean

• HM of a and b is 2ab/(a+b).
• nth terms of Harmonic Progression is  Tn = 1 / [ a + (n-1) d ]

Other Important Formulas

• Sum of first n - natural number is given by:  summation (r=1 to n)  : n (n + 1) / 2.
• Sum of squares of first n - natural number is given by summation (r=1 to n) :[ n ( n + 1 ) (2n + 1)  ] / 6 
• Sum of cubes of first n - natural number is given by summation (r=1 to n) : [n^2 (n+1)^2 ]

/4.

Paging Program

Paging Related C Program: 

Input : 45 

Output : 10 + 10 + 10 + 10 + 5

#include

#include

void main()

{

int numberoflinksperpage=10;

int n,low,high,i=0;

clrscr();

printf("Enter number : ");

scanf("%d",&n);

while(n>numberoflinksperpage)

{

low=i;

high=i+1;

i++;

printf("\n display results from %d to %d ",numberoflinksperpage*low,numberoflinksperpage*high);

n=n-numberoflinksperpage;

}

low=i;

high=i+1;

printf("\n display results from %d to %d ",numberoflinksperpage*low,numberoflinksperpage*(high-1)+n);

getch();

}

Decimal to Binary

Input : any Decimal Number

Output : Binary format 

Logic:

1) Take any natural number say..10.

2)  divide by 2, and find remainder...repeat the same process until u get 0.

divisor number remainder

         2 10 (0)

          ---------------------------------

      2 5 (1)

      ----------------------------------

      2 2 (0)

      ----------------------------------

      2 1 (1)

      ----------------------------------

            0

3) Now look at the remainder pattern from bottom to top, ie. 1010 which is an equivallent for decimal number 10.

Combination of Strings

Input : Any number of Strings

Output : Combinations of Strings

for eg: A,B,C(input)

then Output : 

A

B

C

AB
AC

AD

BC

BD

CD

ABC

mathematical formula : nCr =  n ! / (n-r) ! r !

Algorithm with explanations:

1) Enter the number of strings.

          Let say 3. A,B and C.

2) now loop from i=1 to 2^3-1 = 7 (in general (2^n) -1 ).

3) Observe binary patterns for each of the numbers coming in that loop.

     like in the following case.

Number Bianry Pattern

(A) (B) (C)

  1 0 0 1

2 0 1 0

3 0 1 1

4 1 0 0

5 1 0 1

6 1 1 0

7 1 1 1       

4) now put the appropriate string where 1 appears, and put nothing in case of 0.

ie.

1st entry becomes C

2nd entry B

3 BC

4 A

5 AC

6 AB

7 ABC

Thats all  u need.

Thanks