# How can I determine the input size of an algorithm?

Could you explain to me the input size of the algorithm with these cases? I can't understand the cases with multiple input parameters. Thanks.

algorithm_1( a[1,...,n], b[1,...,n] )
for i ← 1 to legth[a] step ​1 do
for j ← 1 to legth[b] step ​1 do
x++
return 0


-

algorithm_2( a[1,...,n], b[1,...,n] )
return 1


-

algorithm_3( a[1,...,n], n )
for i ← 0 to n step ​1 do
sum += a[i]
return sum


-

algorithm_4( m, n )
for i ← 0 to n step ​1 do
sum += m*2
return sum

• What did you try? – Complexity Mar 27 '18 at 12:35
• You need to add more detail to your question. How $A$ and $B$ are given? – Complexity Mar 27 '18 at 12:45
• Could you be more specific about your problem? The input size is the size of the input. "Size" means size and "input" means input so it's hard to see what you're having difficulty with. – David Richerby Mar 27 '18 at 13:05