We always use nested loops for printing the patterns.
- For the outer loop, we count the number of lines/rows and loop for them.
- Next, for the inner loop, we focus on the number of columns and somehow connect them to the rows by forming a logic such that for each row we get the required number of columns to be printed.
- We print the character inside the inner loop.
- Observe symmetry in the pattern or check if a pattern is a combination of two or more similar patterns.
To analyze the time complexity of this program, let's break it down step by step:
- Outer Loop (i): The outer loop runs
N
times, whereN
is the input parameter. - Inner Loop (j): This loop runs from 1 to i (inclusive), where i is the current value of the outer loop variable.
Let's calculate the total number of iterations of the inner loop across all iterations of the outer loop:
- In the first iteration of the outer loop, the inner loop runs for 1 iteration.
- In the second iteration of the outer loop, the inner loop runs for 2 iterations. And so on, until the last iteration of the outer loop where the inner loop runs for N iterations.
The sum of iterations is:
1 + 2 + 3 + ... + N
This sum is known as the sum of the first N natural numbers, which can be represented as
Therefore, the overall time complexity of the program is
where N is the number of rows/lines (horizontally).
- The additional space used by the code is mainly for temporary variables and the input values.
- The memory used by the nested loops is constant and does not depend on the input size N.
- So, the space complexity of the code is
$O(1)$ , constant space complexity.