Algorithms & data structures
Classic patterns — search, sort, stacks, queues, and practical complexity-aware code.
How to Build a Coordinate Grid with Nested Loops in Python
Generate a 2D list of (row, col) coordinate pairs using nested loops and return the grid structure.
def build_coordinate_grid(rows, cols):
"""Build a 2D grid of (row, col) coordinates using nested loops."""
grid = []
for r in range(rows):
row = []
for c in range(cols):
row.append((r, c))
grid.append(row)
return grid
if __name__ == "__main__":
grid = build_coo…How to Compute the Cartesian Product of Two Lists in Python
Generates all ordered pairs from two lists using itertools.product and prints each combination.
from itertools import product
# Two small input lists
list_a = [1, 2, 3]
list_b = ["x", "y"]
# Compute the Cartesian product
result = list(product(list_a, list_b))
# Display the result
print("Cartesian product of", list_a, "and", list_b, "is:")
for pair in result:
print(pair)Pair Elements with Next Cyclic Neighbor in Python
Create tuples pairing every element with its next element, wrapping around to the first element for the last one.
def cyclic_pairs(lst):
if not lst:
return []
return [(lst[i], lst[(i + 1) % len(lst)]) for i in range(len(lst))]
if __name__ == "__main__":
sample = [1, 2, 3, 4, 5]
result = cyclic_pairs(sample)
print(result)Browse by section
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Algorithms & data structures — Python code examples
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