I have an algorithm of a funtion called sum:

function sum(a,i,j)

z=0

for k=i to j do

{z=z+a[k]}

return(z)

Now i have this algorithms that i got to find what they do and what's their complexity[Big OH Notation.(I'm learning all this by reading.)

Here are the algorithms:

(a.)

m=0

for i=1 to n do

for j=i to n do

{x=sum(a,i,j)

if m<x then m=x}

(b.)

m=0

for i=1 to n do

for j=1 to n do

{x=sum(a,1,n)

if m<x then m=x}

(c.)

m=0

for i=1 to n/4 do

for j=3n/4 to n do

{x=sum(a,i,j)

if m<x then m=x}

(d.)

m=0

for i=1 to n/4 do

for j=3n/4 to n do

{x=sum(a,1,n/2)

if m<x then m=x}

I will appreciate your help in understanding this and some info where i can find more about complexity.