calculate AUC for prediction

how to calculate accuracy of link prediction in social network that is calculated from equation

AUC =( n′ + 0.5 × n′′) / n

where n′ times the missing link having higher similarity value and n′′ times the missing link and nonexistent link having the same similarity value

[Walter Roberson]

I do not understand your explanation of the formula. Or if I do understand it then the formula must be wrong.