Find minimum distance between two words (order preserved) in a big string?

Question

For
e.g 1. "hello how are you" - distance between "hello" and "you" is 3.
e.g 2. "hello how are hello you" - distance is 1
e.g 3. "you are hello" - distance is -1. Order of "hello" and "you" should be preserved.
e.g 4. "hello how are hello" - distance is -1 since "you" did not occur even once.

Answer 1

public static int distance(String str,String a,String b){
        int aIndex=-1;
        int bIndex=-1;
        int minDistance=Integer.MAX_VALUE;
        String[] aS=str.toLowerCase().split("[ \t]+");
        int i=0;
        for(String t:aS){
            if(t.equals(a)){
                aIndex=i;
            }
            if(t.equals(b)){
                bIndex=i;
            }
            if(aIndex!=-1 && bIndex!=-1){
                minDistance= minDistance > Math.abs(bIndex-aIndex) ? bIndex-aIndex : minDistance; 
            }
            i++;
        }
        if(aIndex ==-1 || bIndex==-1)
            return -1;
        else
            return minDistance;
    }