Day 23 of 133
Imbalanced classification + DSA Linked List
SMOTE / class weights / focal loss. PR-AUC, F-beta, MCC.
DSA · NeetCode Linked List
- Copy List With Random PointerDSA · Linked List
Interview questions to prep
- Walk through your pointer hazards — what breaks if you lose track of the head or a prev pointer?
- Can you do this in-place (O(1) extra space)? What's the trick?
- How would you detect / handle a cycle, and prove your method's correctness?
- Add Two NumbersDSA · Linked List
Interview questions to prep
- Walk through your pointer hazards — what breaks if you lose track of the head or a prev pointer?
- Can you do this in-place (O(1) extra space)? What's the trick?
- How would you detect / handle a cycle, and prove your method's correctness?
ML · Imbalanced classification
Interview questions to prep
- Compare random oversampling, undersampling, SMOTE, and class weighting — when does each help?
- Why can SMOTE leak when applied before cross-validation?
Interview questions to prep
- Why does focal loss help with extreme imbalance in object detection?
- Compare focal loss vs class-weighted cross-entropy — when does focal actually win?
Interview questions to prep
- Why is accuracy a terrible metric for imbalanced classification?
- When do you reach for F1, F-beta, MCC, or PR-AUC?
References & further reading
- imbalanced-learn user guide ↗scikit-learn-contrib
- scikit-learn user guide ↗scikit-learn
- Eugene Yan — applied ML writing ↗Eugene Yan