public void set(int pos, long val) {
			if (start == end && start == pos) {
				minIndexVal = pos;
			} else {
				int mid = (start + end) / 2;
				if (pos <= mid)
					left.set(pos, val);
				else
					right.set(pos, val);
				minIndexVal = minIndexVal(left.minIndexVal, right.minIndexVal);
			}
		}