dtypes.h
-----------------------------
#pragma once

typedef unsigned long long u64;
typedef unsigned int u32;
typedef unsigned short u16;
typedef unsigned char u8;

typedef signed long long s64;
typedef signed int s32;
typedef signed short s16;
typedef signed char s8;

const char *natures[25] = {"Hardy", "Lonely", "Brave", "Adamant", "Naughty", "Bold", "Docile", "Relaxed", "Impish", "Lax", "Timid", "Hasty", "Serious", "Jolly", "Naive", "Modest", "Mild", "Quiet", "Bashful", "Rash", "Calm", "Gentle", "Sassy", "Careful", "Quirky"};


typedef struct{

	u32 mul;
	u32 add;
	u32 rmul;
	u32 radd;

} Rand32;


main.c
-----------------------------
#include "stdafx.h"
#include "dtypes.h"


void advanceXD(u32 seed, Rand32* search);
void reverseXD(u32 seed, Rand32* search);
u16 previewHalfReverse(u32 startSeed, u32 frames, Rand32* search);
u16 previewHalfAdvance(u32 startSeed, u32 frames, Rand32* search);
u32 getPID(u32 seed);
u8 getNature(u32 pid);
u32 runsearch(u16 ivseed1, u16 ivseed2, u16 upid, u16 lpid);
u32 runsearch_pid(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid);
u32 runsearch_rev(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid);
u32 runsearch_pid_rev(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid);
void setMagicNumbers(Rand32* search);

Rand32 nums;



int _tmain(int argc, _TCHAR* argv[])
{
	int jirachi = 0;
	u32 pid;
	u8 iv1, iv2, iv3, iv4, iv5, iv6;

	//i only have 2 jirachis to search, might as well automate the process
	switch(jirachi)
	{
	case 0:
		pid = 0x82F76831;
		iv1 = 28; 
		iv2 = 11; 
		iv3 = 7; 
		iv4 = 29; 
		iv5 = 17; 
		iv6 = 7;
	break;

	case 1:
		pid = 0x7C805A75;
		iv1 = 25; 
		iv2 = 0; 
		iv3 = 12; 
		iv4 = 18; 
		iv5 = 26; 
		iv6 = 16;
	break;

	default:
		pid = 0;
		iv1 = 0; 
		iv2 = 0; 
		iv3 = 0; 
		iv4 = 0; 
		iv5 = 0; 
		iv6 = 0;
	}


	//make half seeds out of ivs
	u16 ivseed1 = (iv1 + (iv2 << 5) + (iv3 << 5));
	u16 ivseed2 = (iv6 + (iv4 << 5) + (iv5 << 5));

	//split pids into half seeds
	u16 lpid = pid & 0xFFFF;
	u16 hpid = pid >> 16;

	setMagicNumbers(&nums);


	u32 searchresult = (runsearch(ivseed1, ivseed2, hpid, lpid) || runsearch(ivseed1 + 0x8000, ivseed2, hpid, lpid) || runsearch(ivseed1, ivseed2 + 0x8000, hpid, lpid) || runsearch(ivseed1 + 0x8000, ivseed2 + 0x8000, hpid, lpid));
	searchresult += (runsearch_pid(ivseed1, ivseed2, hpid, lpid) || runsearch_pid(ivseed1 + 0x8000, ivseed2, hpid, lpid) || runsearch_pid(ivseed1, ivseed2 + 0x8000, hpid, lpid) || runsearch_pid(ivseed1 + 0x8000, ivseed2 + 0x8000, hpid, lpid));
	searchresult += (runsearch_rev(ivseed1, ivseed2, hpid, lpid) || runsearch_rev(ivseed1 + 0x8000, ivseed2, hpid, lpid) || runsearch_rev(ivseed1, ivseed2 + 0x8000, hpid, lpid) || runsearch_rev(ivseed1 + 0x8000, ivseed2 + 0x8000, hpid, lpid));
	searchresult += (runsearch_pid_rev(ivseed1, ivseed2, hpid, lpid) || runsearch_pid_rev(ivseed1 + 0x8000, ivseed2, hpid, lpid) || runsearch_pid_rev(ivseed1, ivseed2 + 0x8000, hpid, lpid) || runsearch_pid_rev(ivseed1 + 0x8000, ivseed2 + 0x8000, hpid, lpid));

	if (searchresult > 0)
	{
		printf_s("%X\n\n", searchresult);
	}
	else
	{
		printf_s("No result.\n\n");
	}


	while(1);
	return 0;
}



void advanceXD(u32 seed, Rand32* search)
{

	seed = (seed * search->mul) + search->add;
}


void reverseXD(u32 seed, Rand32* search)
{

	seed = (seed * search->rmul) + search->radd;
}


//shows seed on -frames from seed input
u16 previewHalfReverse(u32 startSeed, u32 frames, Rand32* search)
{
	for (u32 i = 0; i < frames; i++)
	{
		startSeed = ((startSeed * search->rmul) + search->radd) & 0xFFFFFFFF;
	}
	return (u16)(startSeed >> 16);
}


//shows seed on +frames from seed input
u16 previewHalfAdvance(u32 startSeed, u32 frames, Rand32* search)
{
	for (u32 i = 0; i < frames; i++)
	{
		startSeed = ((startSeed * search->mul) + search->add) & 0xFFFFFFFF;
	}
	return (u16)(startSeed >> 16);
}


//grab xd pid
u32 getPID(u32 seed)
{
	u32 pid;

	pid = (u32)((previewHalfAdvance(seed, 3, &nums) << 16) | (previewHalfAdvance(seed, 4, &nums)));

	return pid;
}


u8 getNature(u32 pid)
{ 
	u8 n = (u8)(pid % 25);

	return n;
}


//search starting w/ ivs, ala colo/xd
u32 runsearch(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid)
{
	u32 seed;

	for (int i = 0; i < 65536; i++)
	{
		seed = (u32)((ivseed2 << 16) + i);

		if ((previewHalfAdvance(seed, 1, &nums) == ivseed1) && (previewHalfAdvance(seed, 2, &nums) == hpid) && (previewHalfAdvance(seed, 3, &nums) == lpid))
			return seed;
	}

	return 0;
}

//start with pids like the normal games
u32 runsearch_pid(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid)
{
	u32 seed;

	for (int i = 0; i < 65536; i++)
	{
		seed = (u32)((hpid << 16) + i);

		if ((previewHalfAdvance(seed, 1, &nums) == lpid) && (previewHalfAdvance(seed, 2, &nums) == ivseed1) && (previewHalfAdvance(seed, 3, &nums) == ivseed2))
			return seed;
	}

	return 0;
}

//ivs but going in reverse
u32 runsearch_rev(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid)
{
	u32 seed;

	for (int i = 0; i < 65536; i++)
	{
		seed = (u32)((ivseed2 << 16) + i);

		if ((previewHalfReverse(seed, 1, &nums) == ivseed1) && (previewHalfReverse(seed, 2, &nums) == hpid) && (previewHalfReverse(seed, 3, &nums) == lpid))
			return seed;
	}

	return 0;
}

//pid but going in reverse
u32 runsearch_pid_rev(u16 ivseed1, u16 ivseed2, u16 hpid, u16 lpid)
{
	u32 seed;

	for (int i = 0; i < 65536; i++)
	{
		seed = (u32)((hpid << 16) + i);

		if ((previewHalfReverse(seed, 1, &nums) == lpid) && (previewHalfReverse(seed, 2, &nums) == ivseed1) && (previewHalfReverse(seed, 3, &nums) == ivseed2))
			return seed;
	}

	return 0;
}


void setMagicNumbers(Rand32* search)
{
	search->mul =  0x41c64e6d;
	search->add =  0x3039;
	search->rmul = 0xeeb9eb65;
	search->radd = 0xfc77a683;
}