package main
import (
"errors"
"fmt"
"math"
"strconv"
"strings"
)
// GetNthDecimalDigit returns the Nth digit after the decimal point.
//
// Examples:
// GetNthDecimalDigit(123.456789, 1) -> 4
// GetNthDecimalDigit(123.456789, 2) -> 5
// GetNthDecimalDigit(123.456789, 3) -> 6
//
// Parameters:
// value - Floating-point number to inspect.
// position - Digit position after the decimal point (1-based).
//
// Returns:
// The requested digit, or 0 if the digit does not exist.
func GetNthDecimalDigit(value float64, position int) (int, error) {
if position < 1 {
return 0, errors.New("position must be a positive integer")
}
// Work with positive values only.
value = math.Abs(value)
// Convert the number to a string with fixed precision.
numberStr := strconv.FormatFloat(value, 'f', 15, 64)
// Locate the decimal point.
decimalPos := strings.Index(numberStr, ".")
if decimalPos == -1 {
return 0, nil
}
// Index of the requested digit.
digitIndex := decimalPos + position
if digitIndex >= len(numberStr) {
return 0, nil
}
// Convert the character digit to an integer.
return int(numberStr[digitIndex] - '0'), nil
}
func main() {
number := 123.456789
fmt.Printf("Number: %.6f\n\n", number)
for i := 1; i <= 6; i++ {
digit, err := GetNthDecimalDigit(number, i)
if err != nil {
fmt.Println("Error:", err)
return
}
fmt.Printf("%d digit after decimal = %d\n", i, digit)
}
fmt.Println("\nAdditional Examples")
fmt.Println("-------------------")
digit, _ := GetNthDecimalDigit(123.456789, 4)
fmt.Printf("123.456789, position 4 -> %d\n", digit)
digit, _ = GetNthDecimalDigit(-98.7654, 2)
fmt.Printf("-98.7654, position 2 -> %d\n", digit)
digit, _ = GetNthDecimalDigit(1.2, 5)
fmt.Printf("1.2, position 5 -> %d\n", digit)
}
/*
run:
Number: 123.456789
1 digit after decimal = 4
2 digit after decimal = 5
3 digit after decimal = 6
4 digit after decimal = 7
5 digit after decimal = 8
6 digit after decimal = 9
Additional Examples
-------------------
123.456789, position 4 -> 7
-98.7654, position 2 -> 6
1.2, position 5 -> 0
*/
