Revert "optimised code"

This reverts commit 973b1bf1fae2f58534ca8c46ffa9ab3c202ebeaa.
Yes or No flag to (0,1)

Yes or No flag to (0,1)
Revert "Revert "optimised code""

This reverts commit 0a21f53a53f04d70df120402c3dc77c3f9e9f2b2.