#0235

Minimum Window Substring

HardDSA40 min25 XP

Problem

Given strings s and t, return the smallest substring of s containing every character of t with required multiplicity. Return an empty string if no window exists.

Why This Matters

Minimum window is the advanced sliding-window pattern: expand until valid, then shrink while still valid.

Function Signature

def min_window(s, t):

Examples

Example 1

Inputs = "ADOBECODEBANC", t = "ABC"

Output"BANC"

BANC is the shortest substring containing A, B, and C.

Constraints

Return the exact requested value.
Handle empty or small inputs when the prompt allows them.
Prefer the target DSA pattern over brute force when the input can grow.

CodePython

def min_window(s, t):
    """
    Input example: s = "ADOBECODEBANC", t = "ABC"
    Return: "BANC"
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return ""

def min_window(s, t):
    """
    Input example: s = "ADOBECODEBANC", t = "ABC"
    Return: "BANC"
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return ""

Visible browser tests run here when available.

Testcases2 visible / 3 hidden categories

Classic window

Inputs = "ADOBECODEBANC", t = "ABC"

Expected"BANC"

The final valid window is shortest.

Repeated requirement

Inputs = "AAABBC", t = "AABC"

Expected"AABBC"

The target needs two As, one B, and one C.

Hidden Test Categories

no valid windowsingle-character targettarget longer than source