add flag for whether to only count coprime residues

cmd/quadraticResidues.go

@@ -26,12 +26,13 @@ import (
 )
 
 var quadraticResiduesN uint
+var quadraticResiduesCoprime bool
 
 func quadraticResidues(cmd *cobra.Command, args []string) {
 	bufStdout := bufio.NewWriter(os.Stdout)
 	defer bufStdout.Flush()
 
-	ch := sieve.QuadraticResidues(quadraticResiduesN, 1000)
+	ch := sieve.QuadraticResidues(quadraticResiduesN, quadraticResiduesCoprime, 1000)
 	for i := 0; ; i++ {
 		v, ok := <-ch
 		if !ok {
@@ -69,4 +70,6 @@ func init() {
 
 	quadraticResiduesCmd.Flags().UintVarP(&quadraticResiduesN, "limit", "n", 0, "upper limit")
 	quadraticResiduesCmd.MarkFlagRequired("limit")
+
+	quadraticResiduesCmd.Flags().BoolVarP(&quadraticResiduesCoprime, "coprime-only", "c", false, "only count residues coprime to the modulus")
 }