what is the difference

[GameOn]

is there some difference between the given two ways

for(int i=0;i<=height;i++){
for(int j=0;j<=width;j++){
if(i!=j) sum+=(width-j)*(height-i);
}
}

here i am just taking into account those values in which i and j have different values and 2nd method is

for(int i=0;i<=height;i++){
for(int j=0;j<=width;j++){
sum+=(width-j)*(height-i);
}
sum-=(width-i)*(height-i);
}

here i am adding those vales as well in my solution but later subtracting them

the 2nd approach is giving the wrong answer but i thing that both are logically same.
???

[Odahk]

May as well substitute the "<="s for "<" as whenever they are equal you are adding 0. Aside from that, give example numbers. I'm getting the same for both.

[GameOn]

well. using "<=" or "<" is not a big prob as it just forcing just 1 more execution of the loop.
here is the sample input
width=592
height=964

the 1st method is giving the right answer that is 81508708664
but going through by 2nd method i am is getting -126050230

[Odahk]

Big numbers. Are you initializing sum to 0 before attempting the second method?

And yeah, it's no big problem but may as well be as efficient as possible.