Create fletcher32.go

add hacktoberfest-label please

Author: dev-priyanshu15

checksum/fletcher32.go

@@ -0,0 +1,22 @@
+// Package checksum provides functions for calculating various checksum values.
+package checksum
+
+import (
+    "fmt"
+)
+
+// Fletcher32 computes the Fletcher-32 checksum of the input data.
+func Fletcher32(data []byte) uint32 {
+    var sum1, sum2 uint32 = 0xff, 0xff
+    for _, byte := range data {
+        sum1 = (sum1 + uint32(byte)) % 0xff
+        sum2 = (sum2 + sum1) % 0xff
+    }
+    return (sum2 << 8) | sum1
+}
+
+// Fletcher32Hex computes the Fletcher-32 checksum of a string and returns it as a hexadecimal string.
+func Fletcher32Hex(input string) string {
+    fletcher := Fletcher32([]byte(input))
+    return fmt.Sprintf("%08X", fletcher)
+}