code: private int jOfI(InfoTree it, int aI, int aSubtreeWeight,
  			int aSubtreeRevPre, int aSubtreePre, int aStrategy, int treeSize) {
  		return aStrategy == LEFT ? aSubtreeWeight - aI
  				- it.info[POST2_SIZE][treeSize - 1 - (aSubtreeRevPre + aI)]
  				: aSubtreeWeight
  						- aI
  						- it.info[POST2_SIZE][it.info[RPOST2_POST][treeSize - 1
  								- (aSubtreePre + aI)]];
  	}
docs: Returns j for given i, result of j(i) form Demaine's algorithm.
  
  @param it
  @param aI
  @param aSubtreeWeight
  @param aSubtreeRevPre
  @param aSubtreePre
  @param aStrategy
  @param treeSize
  @return j for given i