Merge pull request #59 from NotSundarPichai/main

Update fibonacci.go

Author: IamBisrutPyne

snippets/Basics/go/fibonacci.go

@@ -1,6 +1,58 @@
-# Title: Iterative + recursive Fibonacci
-# Topic: Basics
-# Language: go
-# Example: see bottom
+// Metadata Header (MANDATORY)
+// -----------------------------
+// Program Title: Fibonacci Sequence (Iterative)
+// Author: ghostrider2606
+// Date: 2025-10-11
+//
+// Description: Generates the Fibonacci sequence up to the n-th term using an iterative approach.
+//
+// Language: Go
+//
+// Time Complexity: O(n)
+// Space Complexity: O(1)
+// -----------------------------
 
-// Iterative + recursive Fibonacci - placeholder in go
+package main
+
+import "fmt"
+
+// fibonacciIterative generates the first n Fibonacci numbers.
+// Uses uint64 for large numbers.
+func fibonacciIterative(n int) ([]uint64, error) {
+    if n < 0 {
+        return nil, fmt.Errorf("input must be a non-negative integer")
+    }
+    if n == 0 {
+        return []uint64{}, nil
+    }
+    if n == 1 {
+        return []uint64{0}, nil
+    }
+
+    sequence := make([]uint64, n)
+    sequence[0] = 0
+    sequence[1] = 1
+
+    var a, b uint64 = 0, 1
+
+    for i := 2; i < n; i++ {
+        nextVal := a + b
+        sequence[i] = nextVal
+        
+        // Shift values
+        a = b
+        b = nextVal
+    }
+    return sequence, nil
+}
+
+func main() {
+    n_terms := 20
+    result, err := fibonacciIterative(n_terms)
+    
+    if err != nil {
+        fmt.Println("Error:", err)
+    } else {
+        fmt.Printf("Fibonacci sequence (first %d terms): %v\n", n_terms, result)
+    }
+}