File list (Check if you may need any files):
hw1_question2_jingweiz
......................\.DS_Store
......................\batchClassifyWithDT.m
......................\classifyWithDT.m
......................\computeOptimalSplit.m
......................\computeOptimalSplit_1.m
......................\fengle.m
......................\gatherTreeStats.m
......................\pruneAllNodes.m
......................\pruneSingleGreedyNode.m
......................\pruneTree.m
......................\testX.csv
......................\testY.csv
......................\trainDT.m
......................\trainX.csv
......................\trainY.csv
......................\validationX.csv
......................\validationY.csv