arrays - Who owes what PHP script -

i tried make owes script in php, it's harder put in code thought.

i have made example of 5 people below:

person  paid    owes/receivables       480     -26 b       600     94 c       1200    694 d       250     -256 e       0       -506 total   2530     average owe per person = 506     

what trying achieve, script prints out how each person owes, , whom. first approach split people owed money in array, , same people needs paid in array. confused approach still, can't explain afterwards.

this rules of script:

• arrange values of arrays highest first.
• subtract highest receivable highest owes array.
• if receivables value still positive, move on next value in owes array.
• if receivables value negative following: take negative value , subtract original owed, subtract value on receivable array (will 0 on value then). move on next on receivable array.

not sure if makes sense or not. hoping can clarify this.

i've made 2 arrays , thought maybe while or foreach loop values , if sentences it, pretty confused @ point.

you have average value payed each person, have receivable , owed values of each person, need find way distribute value owed evenly among people have receivable value.

using "fair" algorithm , example, value peron e owes person c calculated such:

$valueowedbye * $valuereceivablebyc / $totalreceivablevalue 

this gives weighted distribution of owed value among people have receivable values. using algorithm receivable values should reach 0 @ same time , people higher receivable values bigger part of debt.

ofcourse use different algorithm. decide on algorithm want use before try implement it, try make mathematical model of it, becomes trivial implement.