There could be many reasons why you achieved 100% accuracy.One of them could be:Duplicates in your data which are repetitive in both train and test data.I would suggest you to try the following steps:
1.Check if there are any duplicates in the original data
2. Try a different Train-Test split like 80-20
3.Try k-Fold cross validation
4.Checkout for Precision ...
You are doing the split right, training in the train set and then testing in the test set.
Seems weird yes. With out seeing your data, have you droped the target from the with you are trainning?? This could be a reason why you have a 100% accuracy.
Other thing you could try is to plot the feature importance and check which features are contributing to the ...