Solve Any Pattern Question With This Trick!

Free, complete DSA bootcamp with community-driven learning Free, comprehensive DSA interview preparation in Java with a published schedule. Assignments, notes, and Discord support are available via the description, backed by a fast-growing community. Learners are encouraged to share progress publicly using #DSAwithKunal and #60DaysOfDSA, amplified by an automated retweet bot.

Pattern practice builds core thinking, not just interview tricks Pattern exercises seldom appear verbatim in interviews, yet they sharpen problem-solving. Practicing them builds mastery over loops, variables, input/output, and nested iteration in a concrete way. The habits formed transfer to harder topics and make foundational thinking faster.

A universal three-step framework for any pattern Solve any pattern by applying a universal three-step plan. Set the outer loop to the number of lines (rows) and the inner loop to traverse columns. For each row, deduce how many columns and which element to print at each position, then output exactly that.

Left-aligned star triangle via rows-as-lines, columns-as-count Form a left-aligned triangle where row r has r columns. Use an outer loop over rows and an inner loop over columns to print stars, followed by a newline. Walking through iterations verifies the logic and cements how row and column limits interact.

Solid n-by-n star block with fixed double loops Build a solid square by running n rows and n columns. Print a star for every column, yielding an n×n grid. This is the fixed-size baseline many variations extend.

Deriving decreasing columns: n − r + 1 and indexing insights Create a decreasing triangle by setting columns per row to n − r + 1 with 1-based rows. Switching to 0-based indices changes the relation to n − r. Writing row labels beside column counts exposes the pattern and prevents off-by-one mistakes.

Numbered triangle by printing column indices Output numbers instead of symbols by printing the column index. With r columns in row r, the row shows 1 2 … r. The loop structure stays the same; only the printed element changes.

Symmetric hill with 2n − 1 rows and a piecewise column rule Produce a symmetric hill with 2n − 1 total rows. Columns increase from 1 to n, then decrease using columns = r when r ≤ n and columns = 2n − r when r > n. Mind indexing so the peak and mirror align correctly.

Centering with spaces: spaces = n − columns Center stars by printing spaces before each row. Compute spaces as n − columns for that row, then print spaces followed by stars. Reusing the earlier columns formula yields diamonds and rhombuses effortlessly.

Palindromic number pyramid with mirrored loops Construct a palindromic number pyramid by first printing n − r spaces. Then print numbers descending from r to 1 and ascending from 2 to r. Two inner loops mirror around the center to produce the symmetry.

Centered numeric diamond by deriving c per row Render a centered numeric diamond where each row counts up to c and back down, with c rising to n then falling. Derive c with the same piecewise rule as the hill and print n − c leading spaces. The number sequence expands and contracts around the midpoint.

Concentric number square from minimum wall distance Draw concentric number squares on a 2n − 1 by 2n − 1 grid by assigning each cell the minimum distance to any wall: min(row, col, N − row, N − col) under 0-based indexing. Printing this minimum forms layers; subtracting it from the original n yields the target outer-to-inner values. The guiding pattern remains: fix rows, derive a per-row or per-cell formula, and print exactly what the formula dictates.