Algorithm Notes
Summary: Find All Anagrams In String — notes not yet curated.
Time: Estimate via loops/recurrences; common classes: O(1), O(log n), O(n), O(n log n), O(n^2)
Space: Count auxiliary structures and recursion depth.
Tip: See the Big-O Guide for how to derive bounds and compare trade-offs.
Big-O Guide
Source
"""
Find All Anagrams In String
TODO: Add problem description
"""
from collections import Counter
from src.interview_workbook.leetcode._registry import register_problem
from src.interview_workbook.leetcode._types import Category, Difficulty
class Solution:
def solve(self, *args):
"""Return list of start indices of anagrams of p in s."""
s, p = args
res = []
if len(p) > len(s):
return res
p_count = Counter(p)
s_count = Counter()
l = 0
for r, ch in enumerate(s):
s_count[ch] += 1
if r - l + 1 > len(p):
s_count[s[l]] -= 1
if s_count[s[l]] == 0:
del s_count[s[l]]
l += 1
if s_count == p_count:
res.append(l)
return res
def demo():
"""TODO: Implement demo function."""
pass
register_problem(
id=438,
slug="find_all_anagrams_in_string",
title="Find All Anagrams in a String",
category=Category.SLIDING_WINDOW,
difficulty=Difficulty.MEDIUM,
tags=["string", "sliding_window", "hashmap"],
url="https://leetcode.com/problems/find-all-anagrams-in-a-string/",
notes="",
)