From 94fe973505711daac50a00fd0797580d74f926ff Mon Sep 17 00:00:00 2001
From: agarwalpranay02 <pranayagarwal2511@gmail.com>
Date: Wed, 29 Oct 2025 01:47:47 +0530
Subject: [PATCH 1/5] Create fibonacci_iterative.py

Add fibonacci_iterative implementation
---
 maths/fibonacci_iterative.py | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 maths/fibonacci_iterative.py

diff --git a/maths/fibonacci_iterative.py b/maths/fibonacci_iterative.py
new file mode 100644
index 000000000000..a23a13d1e695
--- /dev/null
+++ b/maths/fibonacci_iterative.py
@@ -0,0 +1,29 @@
+def fibonacci_iterative(n: int) -> int:
+    """
+    Return the n-th Fibonacci number using an iterative approach.
+
+    The function returns the Fibonacci number at index n where:
+    F(0) == 0, F(1) == 1, F(2) == 1, ...
+
+    Examples:
+    >>> fibonacci_iterative(0)
+    0
+    >>> fibonacci_iterative(1)
+    1
+    >>> fibonacci_iterative(7)
+    13
+    """
+    if n < 0:
+        raise ValueError("Input must be a non-negative integer")
+
+    if n == 0:
+        return 0
+    a, b = 0, 1
+    for _ in range(1, n):
+        a, b = b, a + b
+    return b
+
+
+if __name__ == "__main__":
+    # simple demonstration
+    print(fibonacci_iterative(7))  # expected 13

From 9b9884d2d8982e0b2e05b604a992952b8ceb9011 Mon Sep 17 00:00:00 2001
From: agarwalpranay02 <pranayagarwal2511@gmail.com>
Date: Wed, 29 Oct 2025 02:00:13 +0530
Subject: [PATCH 2/5] Update fibonacci_iterative.py

---
 maths/fibonacci_iterative.py | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/maths/fibonacci_iterative.py b/maths/fibonacci_iterative.py
index a23a13d1e695..41156565bf98 100644
--- a/maths/fibonacci_iterative.py
+++ b/maths/fibonacci_iterative.py
@@ -1,9 +1,12 @@
-def fibonacci_iterative(n: int) -> int:
+def fibonacci_iterative(term_index: int) -> int:
     """
-    Return the n-th Fibonacci number using an iterative approach.
+    Return the Fibonacci number at a given index using an iterative approach.
 
-    The function returns the Fibonacci number at index n where:
-    F(0) == 0, F(1) == 1, F(2) == 1, ...
+    Parameters:
+        term_index (int): Index in the Fibonacci sequence. Must be a non-negative integer.
+
+    Returns:
+        int: The Fibonacci number at the specified index.
 
     Examples:
     >>> fibonacci_iterative(0)
@@ -13,17 +16,18 @@ def fibonacci_iterative(n: int) -> int:
     >>> fibonacci_iterative(7)
     13
     """
-    if n < 0:
-        raise ValueError("Input must be a non-negative integer")
+    if term_index < 0:
+        raise ValueError("term_index must be a non-negative integer.")
+
+    if term_index <= 1:
+        return term_index
 
-    if n == 0:
-        return 0
-    a, b = 0, 1
-    for _ in range(1, n):
-        a, b = b, a + b
-    return b
+    prev, curr = 0, 1
+    for _ in range(2, term_index + 1):
+        prev, curr = curr, prev + curr
+    return curr
 
 
 if __name__ == "__main__":
-    # simple demonstration
     print(fibonacci_iterative(7))  # expected 13
+

From 59fec8a5a1efbd466259219276c22c125c406436 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 28 Oct 2025 20:30:33 +0000
Subject: [PATCH 3/5] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 maths/fibonacci_iterative.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/maths/fibonacci_iterative.py b/maths/fibonacci_iterative.py
index 41156565bf98..79b38bb1cb96 100644
--- a/maths/fibonacci_iterative.py
+++ b/maths/fibonacci_iterative.py
@@ -30,4 +30,3 @@ def fibonacci_iterative(term_index: int) -> int:
 
 if __name__ == "__main__":
     print(fibonacci_iterative(7))  # expected 13
-

From 6da3d09cdb77a0f5421cec660d84b3bce4158527 Mon Sep 17 00:00:00 2001
From: agarwalpranay02 <pranayagarwal2511@gmail.com>
Date: Wed, 29 Oct 2025 02:37:27 +0530
Subject: [PATCH 4/5] Update fibonacci_iterative.py

---
 maths/fibonacci_iterative.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/maths/fibonacci_iterative.py b/maths/fibonacci_iterative.py
index 79b38bb1cb96..b356b773ecaf 100644
--- a/maths/fibonacci_iterative.py
+++ b/maths/fibonacci_iterative.py
@@ -3,7 +3,8 @@ def fibonacci_iterative(term_index: int) -> int:
     Return the Fibonacci number at a given index using an iterative approach.
 
     Parameters:
-        term_index (int): Index in the Fibonacci sequence. Must be a non-negative integer.
+        term_index (int): Index in the Fibonacci sequence.
+            Must be a non-negative integer.
 
     Returns:
         int: The Fibonacci number at the specified index.
@@ -30,3 +31,4 @@ def fibonacci_iterative(term_index: int) -> int:
 
 if __name__ == "__main__":
     print(fibonacci_iterative(7))  # expected 13
+

From d11a0c266173d13902412de10c3881448e51dc60 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 28 Oct 2025 21:11:06 +0000
Subject: [PATCH 5/5] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 maths/fibonacci_iterative.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/maths/fibonacci_iterative.py b/maths/fibonacci_iterative.py
index b356b773ecaf..9bbd45ae5c6b 100644
--- a/maths/fibonacci_iterative.py
+++ b/maths/fibonacci_iterative.py
@@ -31,4 +31,3 @@ def fibonacci_iterative(term_index: int) -> int:
 
 if __name__ == "__main__":
     print(fibonacci_iterative(7))  # expected 13
-