Pattern 3

Easy

Number triangle 1..i per row

Problem

Print a number triangle where row i prints 1..i for a given size n.

In simple words

Use one loop for the rows and another for what goes in each row to draw the shape.

The idea

Same triangle shape, but instead of a constant star the inner loop prints its own counter. The loop variable is the output, which is the simplest example of a pattern where position determines content.

The trick

Print `j` rather than a star; the shape logic is unchanged.

←→stepspaceplay

rows5

1/7

Optimal

timeO(n^2)spaceO(1)

1// n = 5 produces:2// 13// 1 24// 1 2 35// 1 2 3 46// 1 2 3 4 57 8for i in 1..n:9  for j in 1..i: print(j)10  newline

Input

grid: 5 × 5

Memory

rows: 5

Output

printed rows: —
rows: 5

Check yourself

3 quick questions about this walkthrough. A wrong answer costs nothing.

Example

Input:: n = 5
Output:: 1 / 1 2 / 1 2 3 / 1 2 3 4 / 1 2 3 4 5

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