[SalesForce] Uploading CSV file,Mapping custom fields to “Address fields” in Account

When i upload a csv it must create account, contact, opportunity.
In my custom lead i am having custom field
company name,
company street,
company city,
comapny state,
company postal code.

When i upload csv file,this fields must be mapped to "Billing Address" field on "Account". How this can be done. i didn't how to map this fileds.

Apex code:

public class FileUploaderAll
{
public FileUploaderAll(ApexPages.StandardController controller) {
}
public PageReference fileAccess() {
return null;
}
public FileUploaderAll(){
}
public string nameFile{get;set;}
public Blob contentFile{get;set;}
String[] filelines = new String[]{};
List<Account> accstoupload;
List<Contact> contoupload;
List<Opportunity> opptoupload;
List<CustomLead__c> custtoupload;
List<String> acctNames;

List<Account> newAccts = new List<Account>();
public Pagereference ReadFile()
{
nameFile=contentFile.toString();
filelines = nameFile.split('\n');
accstoupload = new List<Account>();
contoupload = new List<Contact>();
opptoupload = new List<Opportunity>();
custtoupload = new List<CustomLead__c>();
acctNames = new List<String>();
List<Account> existingAccts =new List<Account>();
for (Integer i=1;i<filelines.size();i++)
{
String[] inputvalues = new String[]{};
inputvalues = filelines[i].split(',');
Account a = new Account();
a.Name = inputvalues[0];
acctNames.add(a.Name);
    accstoupload.add(a);
}
existingAccts = [SELECT Id, Name FROM Account where name in :acctNames];
//create a map with names as key
Map<String, Id> acctNamesIdMap = new Map<String, Id>();
// load the map - this will help you find out if an account name exists already
for (Account acct : existingAccts)
{
acctNamesIdMap.put(acct.Name, acct.Id);
System.debug('******Sai******');
}

for (Account acct : accstoupload)
{
//if account name does not exist in map, add it to list of new accounts
if (!acctNamesIdMap.containsKey(acct.Name))
//if (!acctNamesIdMap.containsKey(acct.Id))
{
newAccts.add(acct);
}

}

try
{

insert newAccts;
ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.info,'AccountName with Account Id are the new Account created.Related Contact and Opportunity also created');
ApexPages.Message msg1 = new ApexPages.Message(ApexPages.severity.info,'AccountName without Account Id are the existing Accounts');
ApexPages.addMessage(msg);
ApexPages.addMessage(msg1);

}
catch (Exception e)
{
ApexPages.Message errormsg = new ApexPages.Message(ApexPages.severity.ERROR,'Account     Name already exist, change Account Name and try again');
ApexPages.addMessage(errormsg);    
}
//return null;
for (Integer i=1;i<filelines.size();i++)
{
String[] inputconvalues = new String[]{};
inputconvalues = filelines[i].split(',');
Contact con = new Contact();
for(account a: accstoupload)
{
con.AccountId = accstoupload[i-1].id;
//con.AccountId = a.Id;
}
//con.Account= inputconvalues[0];
if(con.AccountId!= null){
con.Lastname = inputconvalues[1];
con.Lastname_lead__c = inputconvalues[2];
contoupload.add(con);
}}
try
{
insert contoupload;