hi, Here is the illustration with example say you have two strings 'abcde', 'abdcde', I split them into double letters characters combinations including space in the order and flag the occurrence in sting v1(abcde) and string v2(abdcde). ab bc cd de dc bd V1 1 1 1 1 0 0 V2 1 0 1 1 1 1 v1 intersection v2=3 v1 union v2 =6 so my score is 1 - 3 / 6 =0.5 ... View more