I have a array with the lvl=>xp correspondance and I would make a function that return the lvl for a specific xp. like $lvl = getLvlOf(15084); //return 5
$lvl_correspondance = array(
1=>100,
2=>520,
3=>2650,
4=>6588,
5=>12061,
6=>23542,
...
n=>xxxxxx
);
I search the easyest and ressourceless way to do it.
Sorry for my poor english :(
Assuming the level values in the array are kept sorted, e.g. (it's 100,200,300, 400, etc... and not 200,500,100,300,400), then a simple scan will do the trick:
$xp = 15084;
$last_key = null;
foreach($lvl_correspondenance as $key => $val) {
if ($val < $xp) {
$last_key = $key;
} else {
break;
}
}
That'll iterate through the array, and jump out as soon as the XP level in the array is larger than the XP level you're looking for, leaving the key of that "last" level in $last_key
function getLvlOf($lvl, $int){
foreach($lvl as $level=>$exp){
if($exp > $int){
return $level-1;
}
}
}
it's O(n) so no magic there...
It looks like your array can be computed live -
XP = exp( 3 * ln(LVL) + 4 ) * 2
You can do the same in reverse, in O(1):
LVL = exp(ln(XP/2) - 4 / 3)
I rounded the equation, so there may be a +/- 1 issue
Good Luck!
XP = 0.014*L^4 - 1.83*L^3 + 108.67*L^2 - 1563.36*L + 6830 this is ridiculous, and it would be better if you knew where the numbers came from originallyNot good if you have very high level values, but:
$lvl = $lvl_correspondance[array_search(
max(array_intersect(
array_values($lvl_correspondance),
range(0,$points)
)
),
$lvl_correspondance
)];
You can use array_flip if the xp levels are distinct. Then you can simply access the level number using the xp as index:
$levels = array_flip($lvl_correspondance);
$lvl = $levels[15084];
EDIT: But maybe a function would be better to fetch even the xp levels in between:
function getLvlOf($xp) {
// get the levels in descending order
$levels = array_reverse($GLOBALS['lvl_correspondance'], true);
foreach ($levels as $key => $value) {
if ($xp >= $value)
return $key;
}
// no level reached yet
return 0;
}
If a value has several occurrences, the latest key will be used as its values, and all others will be lost.