adjacency list creation , out of Memory error
- by p1
Hello ,
I am trying to create an adjacency list to store a graph.The implementation works fine while storing 100,000 records. However,when I tried to store around 1million records
I ran into OutofMemory Error :
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOfRange(Arrays.java:3209)
at java.lang.String.(String.java:215)
at java.io.BufferedReader.readLine(BufferedReader.java:331)
at java.io.BufferedReader.readLine(BufferedReader.java:362)
at liarliar.main(liarliar.java:39)
Following is my implementation
HashMap<String,ArrayList<String>> adj = new HashMap<String,ArrayList<String>>(num);
while ((str = in.readLine()) != null)
{
StringTokenizer Tok = new StringTokenizer(str);
name = (String) Tok.nextElement();
cnt = Integer.valueOf(Tok.nextToken());
ArrayList<String> templist = new ArrayList<String>(cnt);
while(cnt>0)
{
templist.add(in.readLine());
cnt--;
}
adj.put(name,templist);
} //done creating a adjacency list
I am wondering, if there is any better way to implement the adjacency list. Also, I know number of nodes right in the begining and , in the future I flatten the list as I visit nodes. Any suggestions ?
Thanks
