Sol ev 1 - intento 1

Bin2Dec.java

public static int bin2dec(SinglyLinkedListNode head) {
    SinglyLinkedListNode tmp = head;
    int count, num;
    count = num = 0;
    while(tmp != null) {
      count++;
      tmp = tmp.next;
    }
    tmp = head;
    for(; count > 0; count--) {
      num += tmp.data * Math.pow(2, count-1);
      tmp = tmp.next;
    }
    return num;
}

ForecastTermometer.java

public static List<Integer> ForecastTermometer(List<Integer> T) {
    List<Integer> ans = new ArrayList<Integer>();
    Stack<Integer> stack = new Stack();

    for (int i = T.size() - 1; i >= 0; --i) {
        while (!stack.isEmpty() && T.get(i) >= T.get(stack.peek())) stack.pop();
        ans.add(stack.isEmpty() ? 0 : stack.peek() - i);
        stack.push(i);
    }
    Collections.reverse(ans); 
    return ans;
}

MergeTwoOrderedList.java

public static SinglyLinkedListNode MergeTwoOrderedList(SinglyLinkedListNode l1, SinglyLinkedListNode l2) {
    if (l1 == null) {
        return l2;
    }
    else if (l2 == null) {
        return l1;
    }
    else if (l1.data < l2.data) {
        l1.next = MergeTwoOrderedList(l1.next, l2);
        return l1;
    }
    else {
        l2.next = MergeTwoOrderedList(l1, l2.next);
        return l2;
    }    
}

PairRemove.java

public static String PairRemove(String s) {
    Stack<Character> stack = new Stack<Character>();

    for(char c:s.toCharArray()) {
        if(!stack.empty()) {
            if(stack.peek() == c) stack.pop();
            else stack.push(c);
        } else stack.push(c);
    }

    String sol = "";
    while(!stack.empty()) {
        sol = stack.peek() + sol;
        stack.pop();
    }

    return sol;
}