Missing Ranges

public class Solution {
    public List<String> findMissingRanges(int[] vals, int start, int end) {
        int pre = start-1;
        List<String> res= new List<String>();
        for(int i=0;i<=vals.length;i++){
            int cur = (i==vals.length?)end: vals[i];
            if(cur-pre>1){
                res.add(getRange(vals, pre+1, cur-1));
            }
            pre = cur;
        }
        return res;
    }
    public String getRange(int[] v, int f, int t){
        return (f==t?)String.valueOf(f): from+"->"+ to;
    }
}