trigger to rollup opportunity amount on Account field where opportunity record type is "Revenue Type" Opportunity field: Opty_Amount_C Account field: Total_Opty_Amount_C

Please refer below code

trigger rollupopp on Opportunity (after delete,after update,after insert,after undelete) {
    set<ID>AccIds = new set<ID>();   
    if(trigger.isinsert || trigger.isundelete){
        for(opportunity opp : trigger.new){
            AccIds.add(opp.AccountId);
        }
    }
    if(trigger.isdelete){
        for(opportunity opp : trigger.old){
            AccIds.add(opp.AccountId);           
        }        
    }
    if(trigger.isupdate){
        for(opportunity opp:trigger.new){
            AccIds.add(opp.AccountId);
            if(trigger.oldmap.get(opp.id).AccountId != opp.AccountId && trigger.oldmap.get(opp.id).AccountId != null ){
                AccIds.add(trigger.oldmap.get(opp.id).AccountId);
            }            
        }
    }    
    map<id,double> amtmap = new map<id,double>();
    for(aggregateresult ag : [select AccountId ,SUM(Opty_Amount_C) SOA,count(id) cc from opportunity where AccountId in:AccIds AND RecordType.Name = 'Revenue Type' group by AccountId]){
        amtmap.put((ID)ag.get('AccountId'), double.valueof(ag.get('SOA')));
       // amtmap.put((ID)ag.get('AccountId'), double.valueof(ag.get('cc')));
    }
    list<account>acclist = new list<account>();
    for(id iid : AccIds){
        account acnt = new account(id=iid);
        if(amtmap.containskey(iid)){
            acnt.Total_Opty_Amount_C = amtmap.get(iid);
        }else{
            acnt.Total_Opty_Amount_C = 0;
        } 
        acclist.add(acnt);       
    }
    if(acclist.size()>0){
        update acclist;
    }
}