Faster way of doing this?

Question

Is there a faster way to do either of these and accomplish the same result?
     public int getXPForLevel(int level) {
          int points = 0;
          int output = 0;
          for (int lvl = 1; lvl <= level; lvl++) {
               points += Math.floor((double)lvl + 300.0 * Math.pow(2.0, (double)lvl / 7.0));
               if (lvl >= level)
                    return output;
               output = (int)Math.floor(points / 4);
          return 0;
     public int getLevelForXP(int exp) {
          int points = 0;
          int output = 0;
          for (int lvl = 1; lvl <= 99; lvl++) {
               points += Math.floor((double)lvl + 300.0 * Math.pow(2.0, (double)lvl / 7.0));
               output = (int)Math.floor(points / 4);
               if (output >= exp)
                    return lvl;
          return 0;
     }

Answer 1

You ask for a way to make things faster, and people respond by saying, "why do you want it faster?", or "Are you sure you want it fast? I think your making a mistake by trying to make it faster." Amazing. If you need this fast, you should definitely construct a lookup table and use that for both functions. I haven't verfied your calculator function, but assuming it's right this should work for you. The getLevelForXP is still using a linear search, but it should be much much faster than what your using now. If you need that even faster, you could use a binary search, starting at MAX_LEVEL / 2 to determine whether your target is above or below that level and then moving to the mid-point of the remaining levels; reducing your search time to log-base 2 of your MAX_LEVEL.
M Busche
public class ExpCalculator
    private final int MAX_LEVEL = 99;
    private int[] expTable = new int[MAX_LEVEL+1];
    public ExpCalculator() {
        for (int lvl = 1; lvl <= MAX_LEVEL; ++lvl) {
            expTable[lvl] = calcExp(lvl);
    private int calcExp(int level) {
        int points = 0;
        int output = 0;
        for (int lvl = 1; lvl <= level; lvl++) {
            points += Math.floor((double)lvl + 300.0 * Math.pow(2.0, (double)lvl / 7.0));
            if (lvl >= level)
                return output;
            output = (int)Math.floor(points / 4);
        return 0;
    public int getXPForLevel(int level) {
        return expTable[level];
    public int getLevelForXP(int exp) {
        for (int lvl = 1; lvl <= MAX_LEVEL; lvl++) {
            if(expTable[lvl] > exp)
                return lvl;
        return 0;
}