数据结构：

typedef struct _Page{ // 页面
    int pageID;     //页号
}Page;
typedef struct _PageQueue{ //页面队列
    Page page;
    struct _PageQueue* next; //下一页面
}PageQueue;
typedef struct _Block{ //块记录结构
    Page *page; //页面
    long time; //最后访问时间
    int state; //页块是否空闲
}Block;
typedef struct _BlockQueue{ //块队列
    Block block;
    struct _BlockQueue *next;
}BlockQueue;
typedef struct process{ // 进程结构
    PageQueue pages; //页面
    unsigned int pageLength; // 页面数
}process;//进程

函数：

BlockQueue* InitializeBlockQueue(unsigned int size); //初始化主存块，把首地址返回，如果分配失败返回NULL
int GetBlockQueueSize(BlockQueue *blockQueue);    //获取块长度
void ResetBlockQueue(BlockQueue *blockQueue);    //清空块内容
void PrintBlockList(BlockQueue *blockQueue, int pageID, int color);   //打印块信息
PageQueue* InitializePageQueue(unsigned int pageLength, int maxPageID);    //初始化页面
void InitializeProcess(process *proc, unsigned int pageSize, unsigned int maxPageID);   //初始化进程
BlockQueue* SearchPage(BlockQueue *blockQueue, Page page);   //搜索特定页面
BlockQueue* SearchIdleBlock(BlockQueue *blockQueue);  //搜索空闲块
BlockQueue* GetOldestBlock(BlockQueue *blockQueue);   //取得主存中停留最久的页面，返回它的地址
void FIFO(BlockQueue *blockQueue, process *proc);   //先进先出算法

代码：

#include<stdio.h>
#include<stdlib.h>
#include<ctype.h>
#include<sys/time.h>
#include<unistd.h>
#define BUSY 1
#define IDLE 0
#define blockNumber 3
#define n 10
int Time = 0;
typedef struct _Page{ // 页面
    int pageID;     //页号
}Page;
typedef struct _PageQueue{ //页面队列
    Page page;
    struct _PageQueue* next; //下一页面
}PageQueue;
typedef struct _Block{ //块记录结构
    Page *page; //页面
    long time; //最后访问时间
    int state; //页块是否空闲
}Block;
typedef struct _BlockQueue{ //块队列
    Block block;
    struct _BlockQueue *next;
}BlockQueue;
typedef struct process{ // 进程结构
    PageQueue pages; //页面
    unsigned int pageLength; // 页面数
}process;//进程
BlockQueue* InitializeBlockQueue(unsigned int size){
     //初始化主存块，把首地址返回，如果分配失败返回NULL
    BlockQueue *p1, *p2;
    BlockQueue *block;
    block = NULL;
    for(int i = 0; i < size; ++i){
        p1 = (BlockQueue*)malloc(sizeof(BlockQueue));
        p1->block.time = 0;
        p1->block.state = 0;
        p1->block.page = NULL;
        p1->next = NULL;
        if(block == NULL) block = p1;
        else p2->next = p1;
        p2 = p1;
    }
    return block;
}
int GetBlockQueueSize(BlockQueue *blockQueue){
    //获取块长度
    BlockQueue *presentBlock;
    presentBlock = blockQueue;
    int blockQueueSize = 0;
    while(presentBlock != NULL){
        blockQueueSize++;
        presentBlock = presentBlock->next;
    }
    return blockQueueSize;
}
void ResetBlockQueue(BlockQueue *blockQueue){
    //清空块内容
    BlockQueue *presentBlock;
    presentBlock = blockQueue;
    while(presentBlock != NULL){
        presentBlock->block.page = NULL;
        presentBlock->block.state = IDLE;
        presentBlock->block.time = 0;
        presentBlock = presentBlock->next;
    }
}
void PrintBlockList(BlockQueue *blockQueue, int pageID, int color){
    //打印块信息
    BlockQueue *presentBlock;
    char strl[5], *str2;
    presentBlock = blockQueue;
    while(presentBlock != NULL){
        if(presentBlock->block.state == IDLE)
            printf("|    |\n");
        else{
            printf("| %d  |\n", presentBlock->block.page->pageID);
        }
        presentBlock = presentBlock->next;
    }
    printf("\n");
}
PageQueue* InitializePageQueue(unsigned int pageLength, int maxPageID){
    //初始化页面
    srand(100);
    PageQueue *head;
    head = NULL;
    PageQueue *p, *q;
    for(int i = 0; i < pageLength; ++i){
        p = (PageQueue*)malloc(sizeof(PageQueue));
        p->page.pageID = (int)(rand() % (maxPageID + 1));
        printf("%d ", p->page.pageID);
        p->next = NULL;
        if(head == NULL) head = p;
        else q->next = p;
        q = p;
    }
    printf("\n");
    return head;
}
void InitializeProcess(process *proc, unsigned int pageSize, unsigned int maxPageID){
    //初始化进程
    printf("进程初始化：\n");
    proc->pageLength = pageSize;
    proc->pages.next = InitializePageQueue(pageSize, maxPageID);
}
BlockQueue* SearchPage(BlockQueue *blockQueue, Page page){
    //搜索特定页面
    BlockQueue *p;
    int blockSize;
    p = blockQueue;
    while(p != NULL){
        if(p->block.page != NULL){
            if(p->block.page->pageID == page.pageID)
                return p;
        }
    }
    return NULL;
}
BlockQueue* SearchIdleBlock(BlockQueue *blockQueue){
    //搜索空闲块
    BlockQueue *p;
    p = blockQueue;
    while(p != NULL){
        if(p->block.state == IDLE)
            return p;
        else p = p->next;
    }
    return NULL;
}
BlockQueue* GetOldestBlock(BlockQueue *blockQueue){
    //取得主存中停留最久的页面，返回它的地址
    BlockQueue *p;
    p = blockQueue;
    if(p == NULL) return p;
    int cnt = 0, cur = 0;
    int t = p->block.time;
    while(p != NULL){
        if(t > p->block.time){
            t = p->block.time;
            cur = cnt;
        }
        p = p->next;
        cnt++;
    }
    BlockQueue *q;
    q = blockQueue;
    cnt = 0;
    while(q != NULL){
        if(cnt == cur) return q;
        q = q->next;
        cnt++;
    }
}
void FIFO(BlockQueue *blockQueue, process *proc){
    //先进先出算法
    int blockQueueSize = GetBlockQueueSize(blockQueue);
    PageQueue *currentPage;
    currentPage = proc->pages.next;
    BlockQueue *p;
    p = blockQueue;
    int count = 0, cnt = 0;
    while(currentPage != NULL){
        int ok = 0;
        p = blockQueue;
        Time++;
        while(p != NULL){
            if(p->block.page !=NULL && p->block.page->pageID == currentPage->page.pageID){
                ok = 1;
                break;
            }
            p = p->next;
        }
        if(ok){
            PrintBlockList(blockQueue, currentPage->page.pageID, 0);
        }
        else{
            BlockQueue *block;
            block = SearchIdleBlock(blockQueue);
            if(block != NULL){
                block->block.state = BUSY;
                block->block.time = Time;
                block->block.page = (Page*)malloc(sizeof(Page));
                block->block.page->pageID = currentPage->page.pageID;
                PrintBlockList(blockQueue, currentPage->page.pageID, 1);
            }
            else{
                BlockQueue *block;
                block = GetOldestBlock(blockQueue);
                block->block.time = Time;
                block->block.page->pageID = currentPage->page.pageID;
                PrintBlockList(blockQueue, currentPage->page.pageID, 2);
            }
        }
        currentPage = currentPage->next;
        cnt++;
    }
    printf("%d\n", cnt);
}
int main(){
    int pageNumber;
    scanf("%d", &pageNumber);
    printf("Block Number : %d, Page Number : %d\n", blockNumber, pageNumber);
    BlockQueue *blocks;
    process proc;
    InitializeProcess(&proc, pageNumber, n);
    blocks = InitializeBlockQueue(blockNumber);
    FIFO(blocks, &proc);
    ResetBlockQueue(blocks);

    return 0;
}