FIFO算法LRU算法实验c语言

下面是FIFO算法和LRU算法的C语言实现：

FIFO算法实现：

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

#define MAXSIZE 3

int queue[MAXSIZE];
int front = 0, rear = 0;

void enqueue(int data) {
    if ((rear + 1) % MAXSIZE == front) {
        printf("队列已满，无法插入！\n");
        return;
    }
    queue[rear] = data;
    rear = (rear + 1) % MAXSIZE;
}

int dequeue() {
    if (front == rear) {
        printf("队列为空，无法删除！\n");
        return -1;
    }
    int data = queue[front];
    front = (front + 1) % MAXSIZE;
    return data;
}

int main() {
    enqueue(1);
    enqueue(2);
    enqueue(3);
    printf("队列中的元素为：");
    while (front != rear) {
        printf("%d ", dequeue());
    }
    printf("\n");
    return 0;
}

LRU算法实现：

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

#define MAXSIZE 3

typedef struct {
    int key;
    int value;
} Node;

Node cache[MAXSIZE];
int count = 0;

void add(int key, int value) {
    if (count == MAXSIZE) {
        printf("缓存已满，需要进行替换！\n");
        int min_index = 0;
        for (int i = 1; i < MAXSIZE; i++) {
            if (cache[i].key < cache[min_index].key) {
                min_index = i;
            }
        }
        cache[min_index].key = key;
        cache[min_index].value = value;
    } else {
        cache[count].key = key;
        cache[count].value = value;
        count++;
    }
}

int get(int key) {
    for (int i = 0; i < count; i++) {
        if (cache[i].key == key) {
            int value = cache[i].value;
            for (int j = i; j > 0; j--) {
                cache[j].key = cache[j - 1].key;
                cache[j].value = cache[j - 1].value;
            }
            cache[0].key = key;
            cache[0].value = value;
            return value;
        }
    }
    printf("缓存中不存在该元素！\n");
    return -1;
}

int main() {
    add(1, 100);
    add(2, 200);
    add(3, 300);
    printf("缓存中的元素为：\n");
    for (int i = 0; i < count; i++) {
        printf("%d: %d\n", cache[i].key, cache[i].value);
    }
    printf("获取元素2的值为：%d\n", get(2));
    printf("缓存中的元素为：\n");
    for (int i = 0; i < count; i++) {
        printf("%d: %d\n", cache[i].key, cache[i].value);
    }
    return 0;
}