AC:NH turnip price calculator

TurnipPrices.cpp

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

// munged from https://github.com/simontime/Resead

namespace sead
{
class Random
{
public:
  void init();
  void init(uint32_t seed);
  void init(uint32_t seed1, uint32_t seed2, uint32_t seed3, uint32_t seed4);
  uint32_t getU32();
  uint64_t getU64();
  void getContext(uint32_t *seed1, uint32_t *seed2, uint32_t *seed3, uint32_t *seed4) const;

private:
  uint32_t mContext[4];
};

void Random::init()
{
  init(42069);
}

void Random::init(uint32_t seed)
{
  mContext[0] = 0x6C078965 * (seed ^ (seed >> 30)) + 1;
  mContext[1] = 0x6C078965 * (mContext[0] ^ (mContext[0] >> 30)) + 2;
  mContext[2] = 0x6C078965 * (mContext[1] ^ (mContext[1] >> 30)) + 3;
  mContext[3] = 0x6C078965 * (mContext[2] ^ (mContext[2] >> 30)) + 4;
}

void Random::init(uint32_t seed1, uint32_t seed2, uint32_t seed3, uint32_t seed4)
{
  if ((seed1 | seed2 | seed3 | seed4) == 0) // seeds must not be all zero.
  {
    seed1 = 1;
    seed2 = 0x6C078967;
    seed3 = 0x714ACB41;
    seed4 = 0x48077044;
  }

  mContext[0] = seed1;
  mContext[1] = seed2;
  mContext[2] = seed3;
  mContext[3] = seed4;
}

uint32_t Random::getU32()
{
  uint32_t n = mContext[0] ^ (mContext[0] << 11);

  mContext[0] = mContext[1];
  mContext[1] = mContext[2];
  mContext[2] = mContext[3];
  mContext[3] = n ^ (n >> 8) ^ mContext[3] ^ (mContext[3] >> 19);

  return mContext[3];
}

uint64_t Random::getU64()
{
  uint32_t n1 = mContext[0] ^ (mContext[0] << 11);
  uint32_t n2 = mContext[1];
  uint32_t n3 = n1 ^ (n1 >> 8) ^ mContext[3];

  mContext[0] = mContext[2];
  mContext[1] = mContext[3];
  mContext[2] = n3 ^ (mContext[3] >> 19);
  mContext[3] = n2 ^ (n2 << 11) ^ ((n2 ^ (n2 << 11)) >> 8) ^ mContext[2] ^ (n3 >> 19);

  return ((uint64_t)mContext[2] << 32) | mContext[3];
}

void Random::getContext(uint32_t *seed1, uint32_t *seed2, uint32_t *seed3, uint32_t *seed4) const
{
  *seed1 = mContext[0];
  *seed2 = mContext[1];
  *seed3 = mContext[2];
  *seed4 = mContext[3];
}
} // namespace sead

uint32_t pf(float f) {
  return *((uint32_t *)&f);
}
struct TurnipPrices
{
  int32_t basePrice;
  int32_t sellPrices[14];
  uint32_t whatPattern;
  int32_t tmp40;

  void calculate();

  // utility stuff for testing
  sead::Random rng;
  bool randbool()
  {
    return rng.getU32() & 0x80000000;
  }
  int randint(int min, int max)
  {
    return (((uint64_t)rng.getU32() * (uint64_t)(max - min + 1)) >> 32) + min;
  }
  float randfloat(float a, float b)
  {
    uint32_t val = 0x3F800000 | (rng.getU32() >> 9);
    float fval = *(float *)(&val);
    return a + ((fval - 1.0f) * (b - a));
  }
  int intceil(float val)
  {
    return (int)(val + 0.99999f);
  }
};

void TurnipPrices::calculate()
{
  basePrice = randint(90, 110);
  int chance = randint(0, 99);

  // select the next pattern
  int nextPattern;

  if (whatPattern >= 4)
  {
    nextPattern = 2;
  }
  else
  {
    switch (whatPattern)
    {
    case 0:
      if (chance < 20)
      {
        nextPattern = 0;
      }
      else if (chance < 50)
      {
        nextPattern = 1;
      }
      else if (chance < 65)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    case 1:
      if (chance < 50)
      {
        nextPattern = 0;
      }
      else if (chance < 55)
      {
        nextPattern = 1;
      }
      else if (chance < 75)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    case 2:
      if (chance < 25)
      {
        nextPattern = 0;
      }
      else if (chance < 70)
      {
        nextPattern = 1;
      }
      else if (chance < 75)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    case 3:
      if (chance < 45)
      {
        nextPattern = 0;
      }
      else if (chance < 70)
      {
        nextPattern = 1;
      }
      else if (chance < 85)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    }
  }

  whatPattern = nextPattern;

  /*
  if (checkGlobalFlag("FirstKabuBuy")) {
    if (!checkGlobalFlag("FirstKabuPattern")) {
      setGlobalFlag("FirstKabuPattern", true);
      whatPattern = 3;
    }
  }
  */

  for (int i = 2; i < 14; i++)
    sellPrices[i] = 0;
  sellPrices[0] = basePrice;
  sellPrices[1] = basePrice;

  int work;
  int decPhaseLen1, decPhaseLen2, peakStart;
  int hiPhaseLen1, hiPhaseLen2and3, hiPhaseLen3;
  float rate;

  switch (whatPattern)
  {
  case 0:
    // PATTERN 0: high, decreasing, high, decreasing, high
    work = 2;
    decPhaseLen1 = randbool() ? 3 : 2;
    decPhaseLen2 = 5 - decPhaseLen1;

    hiPhaseLen1 = randint(0, 6);
    hiPhaseLen2and3 = 7 - hiPhaseLen1;
    hiPhaseLen3 = randint(0, hiPhaseLen2and3 - 1);

    // high phase 1
    for (int i = 0; i < hiPhaseLen1; i++)
    {
      sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    }

    // decreasing phase 1
    rate = randfloat(0.8, 0.6);
    for (int i = 0; i < decPhaseLen1; i++)
    {
      sellPrices[work++] = intceil(rate * basePrice);
      rate -= 0.04;
      rate -= randfloat(0, 0.06);
    }

    // high phase 2
    for (int i = 0; i < (hiPhaseLen2and3 - hiPhaseLen3); i++)
    {
      sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    }

    // decreasing phase 2
    rate = randfloat(0.8, 0.6);
    for (int i = 0; i < decPhaseLen2; i++)
    {
      sellPrices[work++] = intceil(rate * basePrice);
      rate -= 0.04;
      rate -= randfloat(0, 0.06);
    }

    // high phase 3
    for (int i = 0; i < hiPhaseLen3; i++)
    {
      sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    }
    break;
  case 1:
    // PATTERN 1: decreasing middle, high spike, random low
    peakStart = randint(3, 9);
    rate = randfloat(0.9, 0.85);
    for (work = 2; work < peakStart; work++)
    {
      sellPrices[work] = intceil(rate * basePrice);
      rate -= 0.03;
      rate -= randfloat(0, 0.02);
    }
    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    sellPrices[work++] = intceil(randfloat(1.4, 2.0) * basePrice);
    sellPrices[work++] = intceil(randfloat(2.0, 6.0) * basePrice);
    sellPrices[work++] = intceil(randfloat(1.4, 2.0) * basePrice);
    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    for (; work < 14; work++)
    {
      sellPrices[work] = intceil(randfloat(0.4, 0.9) * basePrice);
    }
    break;
  case 2:
    // PATTERN 2: consistently decreasing
    rate = 0.9;
    rate -= randfloat(0, 0.05);
    for (work = 2; work < 14; work++)
    {
      sellPrices[work] = intceil(rate * basePrice);
      rate -= 0.03;
      rate -= randfloat(0, 0.02);
    }
    break;
  case 3:
    // PATTERN 3: decreasing, spike, decreasing
    peakStart = randint(2, 9);

    // decreasing phase before the peak
    rate = randfloat(0.9, 0.4);
    for (work = 2; work < peakStart; work++)
    {
      sellPrices[work] = intceil(rate * basePrice);
      rate -= 0.03;
      rate -= randfloat(0, 0.02);
    }

    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * (float)basePrice);
    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    rate = randfloat(1.4, 2.0);
    sellPrices[work++] = intceil(randfloat(1.4, rate) * basePrice) - 1;
    sellPrices[work++] = intceil(rate * basePrice);
    sellPrices[work++] = intceil(randfloat(1.4, rate) * basePrice) - 1;

    // decreasing phase after the peak
    if (work < 14)
    {
      rate = randfloat(0.9, 0.4);
      for (; work < 14; work++)
      {
        sellPrices[work] = intceil(rate * basePrice);
        rate -= 0.03;
        rate -= randfloat(0, 0.02);
      }
    }
    break;
  }

  sellPrices[0] = 0;
  sellPrices[1] = 0;
}

int main(int argc, char **argv)
{
  TurnipPrices turnips;

  if (argc == 3)
  {
    turnips.whatPattern = atoi(argv[1]);
    turnips.rng.init(atoi(argv[2]));
  }
  else
  {
    printf("Usage: %s <pattern> <seed>\n", argv[0]);
    return 0;
  }

  turnips.calculate();
  printf("Pattern %d:\n", turnips.whatPattern);
  printf("Sun  Mon  Tue  Wed  Thu  Fri  Sat\n");
  printf("%3d  %3d  %3d  %3d  %3d  %3d  %3d\n",
         turnips.basePrice,
         turnips.sellPrices[2], turnips.sellPrices[4], turnips.sellPrices[6],
         turnips.sellPrices[8], turnips.sellPrices[10], turnips.sellPrices[12]);
  printf("     %3d  %3d  %3d  %3d  %3d  %3d\n",
         turnips.sellPrices[3], turnips.sellPrices[5], turnips.sellPrices[7],
         turnips.sellPrices[9], turnips.sellPrices[11], turnips.sellPrices[13]);

  return 0;
}

I like how you made an analysis of the return as a function of how many friends you have. Nice work!

This is really cool info. I have a different use case: I time travel to various Wednesdays to look for prices greater than 300. When I find that price, I'll use a second switch and ACNH to go to Sunday, buy tons of turnips, and fly to the first switch and sell the turnips. Very nice profit. However the big thing is to find the Wednesday via time travel. It can take hours to find the right day and time. I've used the MeteoNook to find exact times when meteors show up, and was wondering if a similar algorithm could tell me the exact day and time, or at least narrow it down a bit. I'm guessing not, since there is that random function, but thought I'd check around.