#include <stdio.h>
#include <iostream>
using namespace std;
int number=0;
int Pyblock=0;
int opt(int a[])
{
    int i, j, zero = 0, one = 0, two = 0, q = 0;
    int b[Pyblock];
    for (i = 0; i < Pyblock; i++)
    {
        b[i] =-1;  //空为-1 
    }
    for (i = 0; i < number; i++)
    {
        if (i < 3)
        {
            q++;
            for (j = 0; j < Pyblock; j++)
            {
                if (b[j] == -1)
                {
                    b[j] = a[i];
                    break;
                }
            }
        }
        else
        {
            if (b[0] != a[i])
            {
            	if (b[1] != a[i])
				{
					if(b[2] != a[i]){
		                q++;
		                for (int t = i + 1; t < number; t++)
		                {
		                    if (b[0] == a[t])
		                        zero = 1;
		                    else if (b[1] == a[t])
		                        one = 1;
		                    else if (b[2] == a[t])
		                        two = 1;
		                    if (zero == 1 && one == 1 && two == 0)
		                    {
		                        b[2] = a[i];
		                        break;
		                    }
		                    else if (zero == 1 && one == 0 && two == 1)
		                    {
		                        b[1] = a[i];
		                        break;
		                    }
		                    else if (zero == 0 && one == 1 && two == 1)
		                    {
		                        b[0] = a[i];
		                        break;
		                    }
                }
            	}
            	}
            }
        }
        for (int f = 0; f < Pyblock; f++)
        {
            printf("%d\t", b[f]);
        }
        printf("\n");
        zero = 0;
        one = 0;
        two = 0;
    }
    return q;
}

int main()
{
    int o;

    while(1) 
	{
		printf("请输入分配的物理块的个数:\n");
		scanf("%d",&Pyblock);
		printf("\n");
		break;
	}
	
	while(1)
	{
		printf("请输入页面序列个数:\n");
		scanf("%d",&number);			
		printf("\n");
		break;
	}
    int a[number];
    printf("请依次输入页面序列:\n");
    for (int i = 0; i < number; i++)
    {
        cin>>a[i];
    }
    printf("opt页面置换算法：\n");
    o = opt(a);
    printf("缺页%d次，置换%d次, 缺页率:%.2f%% .\n\n\n", o, o - Pyblock,((double)o/number)*100);
    return 0;
}

//4 3 2 1 4 3 5 4 3 2 1 5