⚡ TL;DR
Print the spiral number matrix pattern in Go. Complete working code, expected output, algorithm explanation, and practice variations for beginners learning loops.
The Spiral Number Matrix pattern is a classic loop exercise. Here’s the complete implementation in Go with working code and output.
Pattern to Print
1 2 3 4 5
16 17 18 19 6
15 24 25 20 7
14 23 22 21 8
13 12 11 10 9Implementation
package main
import "fmt"
func main() {
n := 5
matrix := make([][]int, n)
for i := range matrix { matrix[i] = make([]int, n) }
num, top, bottom, left, right := 1, 0, n-1, 0, n-1
for top <= bottom && left <= right {
for i := left; i <= right; i++ { matrix[top][i] = num; num++ }
top++
for i := top; i <= bottom; i++ { matrix[i][right] = num; num++ }
right--
if top <= bottom {
for i := right; i >= left; i-- { matrix[bottom][i] = num; num++ }
bottom--
}
if left <= right {
for i := bottom; i >= top; i-- { matrix[i][left] = num; num++ }
left++
}
}
for _, row := range matrix {
for _, v := range row { fmt.Printf("%3d ", v) }
fmt.Println()
}
}Output
1 2 3 4 5
16 17 18 19 6
15 24 25 20 7
14 23 22 21 8
13 12 11 10 9How It Works
Layer-by-layer approach: walk the outer ring clockwise (top → right → bottom → left), then shrink the boundaries and repeat for the inner rings.
Practice Variations
- Try printing the pattern with a different character (e.g.,
#or+) - Modify the code to accept the pattern size as user input
- Combine this pattern with its inverse to create a more complex shape
Complexity
- Time: O(n²) — the grid or line count grows quadratically
- Space: O(1) — only loop counters are needed
Related Patterns
- Spiral Number Matrix in Python
- Spiral Number Matrix in Dart
- Spiral Number Matrix in Swift
- Floyd’s Triangle in Go
- Pascal’s Triangle in Go
- Palindromic Number Pyramid in Go
FAQ
How do you print the Spiral Number Matrix pattern in Go?
Use nested loops: the outer loop walks through the rows while the inner loop prints the characters or values for each row. The complete Go implementation with expected output is shown in the sections above.
What is the time complexity of the Spiral Number Matrix pattern in Go?
The time complexity is O(n²) and the space complexity is O(1), since the pattern is built with a fixed number of loop counters and printed row by row.
Happy coding!
