LRU置换算法利用栈结构实现

      #include

       #include

#define N 50

int accessList[N];

typedef struct regitStack{

int size;

int *no;

int *head;

int *tail;

}Regit;

struct regitStack *regit;

int count;

int currentSize=0;

int createAccessList();

int createStack();

int* isEixt(int no);

int lru();

void printStack();

int main(){

    createStack();

createAccessList();

lru();

}

int createAccessList(){

int i;

printf("输入访问内存次数:");

scanf("%d",&count);

printf("输入页面访问序列\n");

for( i=0;i

printf("第%d个页面号:",i+1);

scanf("%d",&accessList[i]);

}

return 0;

}

int createStack(){

regit=(Regit*)malloc(sizeof(Regit));

regit->size=5;

regit->no=(int*)malloc(sizeof(int)*regit->size);

regit->head=regit->tail=regit->no;

return 0;

}

int lru(){

int i;

int *temp,*move;

for(i=0;i

        if((temp=isEixt(accessList[i]))==NULL)//访问的页号不在栈内

{

if(currentSizesize)//堆栈未满直接压到顶部

{

*(regit->head)=accessList[i];

regit->head++;

currentSize++;

}else{                    //下移压顶

move=regit->tail;

printf("第%d次访问时置换出%d页\n",i+1,*regit->tail);

while(1){

*move=*(move+1);

move++;

if(move==regit->head-1)

{

*move=accessList[i];

break;

}

}

}

}else{

            

if(accessList[i]!=*(regit->head-1)){  //不在顶时

move=temp;

while(1){

*move=*(move+1);

move++;

if(move==regit->head-1){

*move=accessList[i];

break;

}

}

}

}

printStack();

}

return 0;

}

int* isEixt(int no){

    int *p=regit->tail;

while(p!=regit->head){

if(*p==no){

return p;

}

p++;

}

    return NULL;

}

void printStack(){

int i;

printf("堆栈中的页面号:");

for(i=0;i

printf("%d",regit->no[i]);

}

printf("\n");

}

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