学步园

#include<stdio.h>

typedef unsigned int uint;
uint seed = 2037280626;
const uint park1 = 127773;
const uint park2 = 16807;
const uint park3 = 2836;

/*
random PROC base:DWORD         ; Park Miller random number algorithm
    mov eax, seed              ; from M32lib/nrand.asm
    xor edx, edx
    mov ecx, 127773
    div ecx
    mov ecx, eax
    mov eax, 16807
    mul edx
    mov edx, ecx
    mov ecx, eax
    mov eax, 2836
    mul edx
    sub ecx, eax
    xor edx, edx
    mov eax, ecx
    mov seed, ecx
    div base
    mov eax, edx
    ret
random ENDP

*/

uint random(uint base)
{
	uint a,b;
	uint r;
	
	a = seed % park1 * park2;
	b = seed / park1 * park3;
	a -= b;
	
	seed = a;
	r = a % base;
	return r;
}

uint asmrandom(uint base)
{
	__asm{
	mov eax, seed
    	xor edx, edx
    	mov ecx, park1
    	div ecx
    	mov ecx, eax
    	mov eax, park2
    	mul edx
    	mov edx, ecx
    	mov ecx, eax
    	mov eax, park3
    	mul edx
    	sub ecx, eax
    	xor edx, edx
    	mov eax, ecx
    	mov seed, ecx
    	div base
    	mov eax, edx
	}
}
int main()
{
	int i;
	for(i=0;i<150;i++){
		if(i%10==0)
			puts("");
		printf("%4d",asmrandom(100));
	}
	puts("");
	seed = 2037280626;
	for(i=0;i<150;i++){
		if(i%10==0)
			puts("");
		printf("%4d",random(100));
	}
	puts("");

	return 0;
}