Try something like this @Gujjar
HashMap<String, int> wordCount;
int createProbabilityHash(words):
    int numWords = words.size();
    wordCount = new HashMap<String, int>();
    for (int i = 0;i < numWords; ++i) {
        if wordCount.containsKey(words[i]) {
            wordCount.put(words[i], wordCount.get(words[i]) + 1);
        } else {
            wordCount.put(words[i], 1);
        }
    }