Neural Networks
95 problems
- Affine coupling layer (normalizing flow)Medium
- Teacher forcing — next-token targetsMedium
- Pretraining objective per familyEasy
- Autoencoder forward passEasy
- Basic autograd operationsMedium
- Binary Quantization + Hamming RetrievalMedium
- Conv2D backward (dx, dW)Hard
- Linear forward (Wx + b)Easy
- ReLU forward + backwardEasy
- Sigmoid forward + backwardEasy
- MSE loss + backwardEasy
- Linear backward (chain rule)Medium
- SGD step (in place)Easy
- Train a 2-layer MLP on XORHard
- Warmup + cosine decay LR scheduleEasy
- Cross-entropy gradientMedium
- Convolution — slide a 1D filter (weight sharing)Medium
- Images as tensors — the shapeEasy
- Edge models — magnitude pruningEasy
- Edge models — measure sparsityEasy
- DDPM Reverse (Denoise) StepMedium
- Dense block with 2D convolutionsMedium
- Diffusion forward processMedium
- Backprop — all four gradients for one hidden layerMedium
- From scratch — the batched forward passMedium
- BCE from logits — the stable sigmoid + BCE pairingMedium
- End-to-end binary classifier (ReLU hidden, sigmoid output)Medium
- Binary output head — probability and decisionEasy
- BCE — clip the probabilities so log stays finiteEasy
- Forward pass — arbitrary depthMedium
- Dense layer — count the parametersEasy
- Dense layer — sigmoid forward passEasy
- Overfitting — read the learning curvesEasy
- Ensembling — average models, then predictMedium
- Forward pass — cache the activationsEasy
- Hyperparameter grid-search sizeEasy
- From scratch — derive the parameter shapesEasy
- Parameter or hyperparameter?Easy
- Weight decay — the L2 penalty termEasy
- Why nonlinearity — collapsing two linear layersMedium
- Network — total trainable parametersEasy
- Neuron — one unit, three activationsEasy
- Neuron — the linear score z = wᵀx + bEasy
- Backprop — the output deltaEasy
- Perceptron — the hard threshold unitEasy
- Perceptron — the learning ruleMedium
- Loss — pick the better modelEasy
- Output layer — predict the classEasy
- ReLU — find the dead neuronsEasy
- Dense layer with ReLU (the production hidden default)Easy
- Scaling laws — estimate the power-law exponentMedium
- Sigmoid derivative from the activationEasy
- Softmax with temperatureEasy
- From scratch — does this init break symmetry?Easy
- Network — the two-layer forward passMedium
- Vanishing gradients through sigmoid layersEasy
- Backprop — the weight gradient is an outer productEasy
- Dropout layer (forward & backward)Medium
- Early stopping on validation lossEasy
- Exponential moving average of weightsEasy
- Exponential LR schedulerEasy
- GCN layer (message passing)Medium
- GELU backward (tanh approximation)Medium
- Parameter breakdown of a GPT-2 blockMedium
- The 4× MLP hidden dimensionEasy
- Where loss starts: log(V)Easy
- Depth-aware init for residual projectionsEasy
- Gradient checkpointing forwardEasy
- Clip gradients by global L2 normEasy
- Group normalizationMedium
- Hard Negative Mining for RetrieverMedium
- He weight initializationEasy
- HNSW Greedy Graph SearchHard
- IVF (Inverted File) SearchMedium
- Label-Noise Detection (Confident Learning)Hard
- Leaky ReLU activationEasy
- Learning-rate range testMedium
- Log-softmaxEasy
- Matmul backwardMedium
- MIPS -> L2 ReductionMedium
- Neural ODE forward EulerMedium
- Product Quantization (PQ) Encode + ADCHard
- Random-Hyperplane LSH (Cosine)Medium
- Residual block with shortcutEasy
- SimpleRNN forward — outputs over a sequenceMedium
- In-Batch Sampled Softmax + logQ CorrectionHard
- SELU activationEasy
- BPTT — the gradient-norm trajectoryMedium
- Vanishing or exploding? Classify the regimeEasy
- BPTT — the tanh backward factorEasy
- Softmax backwardMedium
- Softmax from scratchEasy
- Step LR schedulerEasy
- Swish / SiLU activationEasy
- VAE ELBO lossMedium