Added Len{,64} gives back the number of digits of a number.

ints/statistics.go

@@ -62,6 +62,28 @@ func IsPalindromic(n int) bool {
 	return true
 }
 
+// Len returns the number of digits of i (base 10, does not include a sign).
+func Len(i int) int {
+	return Len64(int64(i))
+}
+
+// Len64 returns the number of digits of i (base 10, does not include a sign).
+func Len64(i int64) int {
+	if i == 0 {
+		return 1
+	}
+	if i < 0 {
+		i = 0 - i
+	}
+
+	digits := 0
+	for i > 0 {
+		i /= 10
+		digits++
+	}
+	return digits
+}
+
 // Permutations returns all possible permutations of the the set integers.
 func Permutations(set []int) [][]int {
 	var n = len(set)