I was solving C in Div2 #698 and I have a query

105802847 and 105802880 are my submission the only difference is the line

if(a.get(i)-a.get(i-1)!=0){f=false;} and if(a.get(i)!=a.get(i-1)){f=false;}respectively

The first one got accepted while the second one fails the last tc of sample test

Please tell me why this is happening

Thanks.