devgeekco / wow

Designed and implemented algorithm for calculating 'Who Owes Who' in Group expenses.

WOW - Who Owes Who?

Designed and implemented algorithm for calculating 'Who Owes Who' in Group expenses.

Algorithm

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1. Save users in HashMap - Key: username, Value: total expense

2. Caculate average of expense 'avge'

3. Substracts avgage expense with each users total expense and save uses in different HashMap based of positive and negative return i.e. negativeUsers<>, positiveUsers<>

4. Sort negativeUsers<> in increasing order and positiveUsers<> in decreasing order.

5. Subtract positiveUser.value against negativeUsers.value in a Recursive function

   generateReport(positiveUser, negativeuser) { if(positiveUser.size == 0 or negativeUser.size == 0) return true;

    subValue = positiveUser.Value - negativeUser.value;
    if(subValue == 0 ) then
    	print "negativeUser.key owes positiveUser.key Amount: positiveUser.value";
    	positiveUser.removeKey; negativeUser.removeUser;
    else if (subValue > 0 ) then
    	print "negativeUser.key owes positiveUser.key Amount: negativeUser.value.abs";
    	positiveUser.put(key, subValue); negativeUser.removeUser
    else if (subValue < 0) then
    	print "negativeUser.key owes positiveUser.key Amount: positiveUser.value ";
    	positiveUser.removeUser; negativeUser.put(key, subValue);
    else
    	print "Error!"
   
    // Recursive call
    generateReport(positiveuser, negativeUser);
   
    return true;
   

   }