trigger CONUP on Contact (after update,after insert) {
    Map<Id, Decimal> acctIdToAmount = new Map<Id, Decimal>();
    List<Account> accountsToUpdate = new List<Account>();
    Map<ID,RecordType> typeMap = New Map<ID,RecordType>([Select ID, DeveloperName From RecordType Where sObjectType = 'CONTACT']);
    for (CONTACT CON : trigger.new) {
          // If the Record Type = Intake Form
          if (typeMap.get(CON.RecordTypeId).DeveloperName == 'C2B' || typeMap.get(CON.RecordTypeId).DeveloperName == 'D2B') {
            //    Get the Contact Amount into a temp variable
            Decimal sum = CON.PAID_AMOUNT__c == null ? 0 : CON.PAID_AMOUNT__c;
            //    Sum it up with the already collected Amount    
            if(acctIdToAmount.containsKey(CON.AccountId))
                sum += acctIdToAmount.get(CON.AccountId); 
            
            //    Make a map with AccountId as Key and Amount as value     
             acctIdToAmount.put(CON.AccountId, sum);
          }
          else if(typeMap.get(CON.RecordTypeId).DeveloperName == 'E2B') {
              Decimal sum = 0;

            if(acctIdToAmount.containsKey(CON.AccountId))
                sum = acctIdToAmount.get(CON.AccountId);

            sum -= CON.PAID_AMOUNT__c == null ? 0 : CON.PAID_AMOUNT__c; 
                 
             acctIdToAmount.put(CON.AccountId, sum);    
          }      
    }

    for(Id accId : acctIdToAmount.keyset()) {
        Account acc;
        if(acctIdToAmount.get(accId) >= 0)
               acc = new Account(Id = accId, TOTAL_AMOUNT__c = acctIdToAmount.get(accId));
        else
               acc = new Account(Id = accId, PENDING_AMOUNT__c = acctIdToAmount.get(accId));
        accountsToUpdate.add(acc);
    }

    if(!accountsToUpdate.isEmpty())
        update accountsToUpdate;
}



mactualu using the above code ....and the error is:duplicate value found: <unknown> duplicates value on record with id: <unknown>......can i get the code rectified ....to slove this issue