NumPy

0 / 170 solved · Easy 59 · Medium 63 · Hard 48

#		Title	Difficulty
1	○	Import NumPy	Easy
2	○	NumPy Version	Easy
3	○	Null Vector of Size 10	Easy
4	○	Memory Size of an Array	Easy
5	○	Documentation of np.add	Easy
6	○	Null Vector, Fifth Value 1	Easy
7	○	Range Vector 10–49	Easy
8	○	Reverse a Vector	Easy
9	○	3×3 Matrix 0–8	Easy
10	○	Indices of Non-Zero Elements	Easy
11	○	Identity Matrix	Easy
12	○	3×3×3 Random Array	Easy
13	○	Min and Max	Easy
14	○	Mean Value	Easy
15	○	1 on Border, 0 Inside	Easy
16	○	Add a Zero Border	Easy
17	○	NaN Expression Results	Easy
18	○	Values Below the Diagonal	Easy
19	○	Checkerboard Pattern	Easy
20	○	Unravel 100th Index	Easy
21	○	Checkerboard with tile()	Easy
22	○	Normalize a Matrix	Easy
23	○	RGBA dtype Size	Easy
24	○	Matrix Product	Easy
25	○	Negate Elements 3–8	Easy
26	○	Builtin sum vs np.sum	Easy
27	○	Which Expressions Are Legal?	Easy
28	○	Results of Edge Expressions	Easy
29	○	Round Away From Zero	Easy
30	○	Common Values	Easy
31	○	Ignore NumPy Warnings	Easy
32	○	sqrt(-1) vs emath.sqrt(-1)	Easy
33	○	Yesterday and Tomorrow	Easy
34	○	Dates in July 2016	Medium
35	○	Compute ((A+B)*(-A/2))	Medium
36	○	Integer Part	Medium
37	○	Rows Ranging 0–4	Medium
38	○	Build Array from Generator	Easy
39	○	Vector 0–1 Both Excluded	Medium
40	○	Sort a Vector	Medium
41	○	Sum with add.reduce	Medium
42	○	Are Two Arrays Equal?	Medium
43	○	Make an Array Read-Only	Medium
44	○	Cartesian to Polar	Medium
45	○	Replace Max with 0	Medium
46	○	Coordinate Grid	Medium
47	○	Cauchy Matrix Determinant	Medium
48	○	Min/Max of int8	Medium
49	○	Full Array as String	Medium
50	○	Closest Value to a Scalar	Medium
51	○	Position + Color Struct	Medium
52	○	Point-by-Point Distances	Medium
53	○	Float32 to Int32 In Place	Medium
54	○	Parse a Messy CSV	Medium
55	○	Enumerate a 2D Array	Medium
56	○	2D Gaussian Array	Medium
57	○	Place p Elements Randomly	Medium
58	○	Subtract Row Means	Medium
59	○	Sort by nth Column	Medium
60	○	Has Null Columns?	Medium
61	○	Nearest Value	Medium
62	○	Sum via Iterator	Medium
63	○	Array with a Name	Medium
64	○	Add 1 at Indexed Positions	Hard
65	○	Accumulate by Index List	Hard
66	○	Count Unique Colors	Medium
67	○	Sum Over Last Two Axes	Hard
68	○	Means of Subsets	Hard
69	○	Diagonal of a Dot Product	Hard
70	○	Interleave 3 Zeros	Hard
71	○	Multiply (5,5,3) by (5,5)	Hard
72	○	Swap Two Rows	Hard
73	○	Unique Triangle Segments	Hard
74	○	Invert a bincount	Hard
75	○	Sliding Window Average	Hard
76	○	Rolling Windows (shift by 1)	Hard
77	○	Negate Float Array In Place	Hard
78	○	Distance Point to Lines	Hard
79	○	Distance Points to Lines	Hard
80	○	Centered Subpart with Fill	Hard
81	○	Generate Shifted Rows	Hard
82	○	Matrix Rank	Hard
83	○	Most Frequent Value	Medium
84	○	All Contiguous 3×3 Blocks	Hard
85	○	Make a Matrix Symmetric	Hard
86	○	Sum of p Matrix Products	Hard
87	○	Block-Sum (4×4 blocks)	Hard
88	○	Game of Life Step	Hard
89	○	n Largest Values	Hard
90	○	Cartesian Product	Hard
91	○	Record Array from Array	Hard
92	○	Cube Each Element	Hard
93	○	Rows Containing Each Row of B	Hard
94	○	Rows with Unequal Values	Hard
95	○	Ints to Binary Matrix	Hard
96	○	Extract Unique Rows	Hard
97	○	Outer Product with einsum	Hard
98	○	Equidistant Path Sampling	Hard
99	○	Multinomial Rows	Hard
100	○	Bootstrap Confidence Interval	Hard
101	○	Full Array Like a Prototype	Easy
102	○	Reproducible Random Integers (Generator API)	Easy
103	○	Binomial Draws (Generator API)	Medium
104	○	Save and Load a .npy Array	Easy
105	○	Save Multiple Named Arrays with savez	Medium
106	○	Selective CSV Import	Medium
107	○	Impute Missing Values with the Column Mean	Medium
108	○	Delete Rows and Columns	Easy
109	○	Sort Rows by a Given Column	Easy
110	○	Locate Elements Matching a Condition	Easy
111	○	Stack Two Vectors as Rows	Easy
112	○	Concatenate Two Vectors End-to-End	Easy
113	○	Stack Two Matrices Along a New Axis	Medium
114	○	Count Occurrences of Each Unique Value	Easy
115	○	Index of First Occurrence of Each Unique Value	Easy
116	○	Weighted Average	Easy
117	○	Correlation Matrix Between Rows	Medium
118	○	Histogram Bin Counts	Easy
119	○	Peak-to-Peak Range per Row	Easy
120	○	Strip Prefixes and Map Categories to Codes	Medium
121	○	Row-wise Stable Softmax	Easy
122	○	One-Hot Encode an Index Array	Easy
123	○	Dense Layer Forward with Leaky ReLU	Easy
124	○	Padding Mask from Sequence Lengths	Easy
125	○	Layer Normalization Forward	Easy
126	○	Top-k Accuracy	Easy
127	○	Cross-Entropy Loss Straight from Logits	Medium
128	○	Batch Norm Forward with Running Stats	Medium
129	○	One Lloyd Step of k-Means	Medium
130	○	kNN Predict with a Deterministic Tie-Break	Medium
131	○	Confusion Matrix and Macro F1	Medium
132	○	Pairwise IoU Matrix Between Box Sets	Medium
133	○	Logistic Loss and Gradient, Vectorized	Medium
134	○	Ridge Regression in Closed Form	Medium
135	○	Max-Pool Forward with Stride	Medium
136	○	Gradient of Softmax Cross-Entropy	Hard
137	○	Backprop Gradients for a Two-Layer MLP	Hard
138	○	Scaled Dot-Product Attention, Causal	Hard
139	○	Greedy Non-Maximum Suppression	Hard
140	○	ROC AUC by Rank Statistic, with Ties	Hard
141	○	Coalesce Two Rating Columns	Easy
142	○	Drop Rows Containing Any Missing Value	Easy
143	○	Winsorize at Given Percentiles	Easy
144	○	Month-over-Month Growth Rate	Easy
145	○	Average Order Value per Customer	Medium
146	○	Percentile Rank Each Value	Medium
147	○	Number the Rows Within Each Group	Medium
148	○	Forward-Fill Missing Values	Medium
149	○	Convert Amounts via a Rate Lookup	Medium
150	○	Standardize Each Column Safely	Medium
151	○	Top-N Rows per Category	Hard
152	○	Longest Streak of Consecutive Active Days	Hard
153	○	Classify Each Indexing Form as View or Copy	Medium
154	○	Find the Unit-Stride Axis	Medium
155	○	Resolve a Broadcast Shape by Hand	Medium
156	○	Which Reductions Silently Change dtype	Medium
157	○	may_share_memory vs shares_memory	Medium
158	○	Predict Result dtypes Under NEP 50	Hard
159	○	In-Place vs Out-of-Place Mixed dtypes	Hard
160	○	Build a Broadcast View With a Zero Stride	Hard
161	○	The reduceat Non-Monotonic Trap	Hard
162	○	Log Returns from a Price Series	Easy
163	○	Interpolate a Curve with Flat Extrapolation	Easy
164	○	Maximum Drawdown with Peak and Trough	Medium
165	○	Rolling Z-Score Over a Trailing Window	Medium
166	○	RiskMetrics EWMA Volatility	Medium
167	○	OLS Beta and R-Squared via Least Squares	Medium
168	○	Global Minimum-Variance Portfolio Weights	Medium
169	○	Attach the Prevailing Quote to Each Trade	Hard
170	○	Monte Carlo Call with Antithetic Variates	Hard