FIFO、LRU和最优页面置换算法的C++实现_c语言编写fifo算法和lru算法

#include<iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
int arr[10];
void getrandom();
int FIFO(int length);
int OPA(int length);
int LRU(int length);
int main()
{
	getrandom();
	for (int i = 0; i < 10; i++)
	{
		cout << arr[i]<<' ';
	}
	cout << endl;
	int n;
	cin >> n;
	cout << FIFO(n) << endl;
	cout << OPA(n) << endl;
	cout << LRU(n) << endl;
	return 0;
}
 
void getrandom()
{
	for (int i = 0; i < 10; i++)
	{
		arr[i]= rand() % 9  + 1;
	}
}
 
int FIFO(int length)
{
	int* page;
	int* sequence;
	page = new int[length];
	sequence = new int[length];
	for (int i = 0; i < length; i++)
	{
		page[i] = 10;
		sequence[i] = 0;
	}
	int j = 0;
	int num = 0;
	while (j < 10)
	{
		int flag = 0;
		for (int i = 0; i < length; i++)
		{
			if (page[i] == arr[j])
			{
				flag++;
				break;
			}
		}
		if (flag == 0)
		{
			int fl = 0;
			int first = sequence[0];
			for (int i = 0; i < length; i++)
			{
				if (sequence[i] < first)
				{
					first = sequence[i];
					fl = i;
				}
			}
			page[fl] = arr[j];
			sequence[fl]++;
			num++;
		}
		j++;
	}
	return num;
}
 
int OPA(int length)
{
	int* page;
	page = new int[length];
	for (int i = 0; i < length; i++)
	{
		page[i] = 10;
	}
	int* note;
	note = new int[length];
	for (int i = 0; i < length; i++)
	{
		note[i] = 0;
	}
	int num=0;
	int j = 0;
	while (j < 10)
	{
		int flag = 0;
		for (int i = 0; i < length; i++)
		{
			if (page[i] == arr[j])
			{
				flag++;
				break;
			}
		}
		if (flag == 0)
		{
			for (int i = 0; i < length; i++)
			{
				for (int t = j; t < 10; t++)
				{
					if (page[i] == arr[t])
					{
						note[i] = t;
						break;
					}
				}
			}
			int fl = 0;
			for (int i = 0; i < length; i++)
			{
				if (note[i] == 0)
				{
					fl++;
					page[i] = arr[j];
					num++;
					break;
				}
			}
			if (fl == 0)
			{
				int fg = note[0];
				int a = 0;
				for (int i = 0; i < length; i++)
				{
					if (note[i] > note[0])
					{
						fg = note[i];
						a = i;
					}
			     }
				page[a] = arr[j];
				num++;
			}
		}
		j++;
	}
	return num;
}
 
int LRU(int length)
{
	int* page;
	page = new int[length];
	int* count;
	count = new int[length];
	for (int i = 0; i < length; i++)
	{
		page[i] = 10;
		count[i] = 0;
	}
	int num = 0;
	int j = 0;
	while (j < 10)
	{
		int flag = 0;
		for (int i = 0; i < length; i++)
		{
			if (page[i] == arr[j])
			{
				flag++;
				break;
			}
		}
		if (flag == 0)
		{
			int min = count[0];
			int fl = 0;
			for (int i = 0; i < length; i++)
			{
				if (count[i] < min)
				{
					min = count[i];
					fl = i;
				}
			}
			page[fl] = arr[j];
			count[fl] = j;
			num++;
		}
		j++;
	}
	return num;
}

这只是最简单的实现，不一定完全正确，有误之处，多多指教