Bubble sort - an array of linked lists &

Ordering process

To sort a set of data, e.g. [5] 2,3,1,4

• After the first round of sorting [2,3,1,4,5]
• After the second round of the sort [2,1,3,4,5]
• After the third round of the sort [1,2,3,4,5]

Bubble sort array

    int flag=0,temp;
    int s[10]={9,8,7,6,5,4,3,2,1,0};  //定义数组并赋值
    for(int i=0;i<10;i++)
    {
        for(int j=0;j<10-i-1;j++)
        {
            if(s[j]>s[j+1]){
            temp=s[j];
            s[j]=s[j+1];
            s[j+1]=temp;
                flag=1;
            }
        }
        if(flag==0)
            break;
    }

The code number, the outer loop control cycle, the sequence is complete 10 cycles in the worst case; comparing the number of inner loop control; In Flag used to determine whether the exchange occurred, if no switching occurs, then the sort has been completed, then you do not need to cycle 10 times;

Bubble sort the list

The following is the code for the node is not the lead (i.e., a first node data field is not empty) list of

void swap(){
    STUDENT *head_front ;
    head_front=(STUDENT *)malloc(sizeof(STUDENT)); //为链表设置一个数据域为空的头节点
    head_front->next=head;    
    STUDENT *t, *p,*q,*temp;
    for(int i=0;i<sum+1;i++)  //上面加了一个结点，所以这而是sum+1
    {
        int flag = 1;
        t=head_front;
        p=t->next;
        q=p->next;
        for(int j=0;j<sum-i-1;j++)
        {
            if(p->num > q->num)
            {
                t->next = q;
                p->next = q->next;
                q->next = p;
                temp = p; p = q;q = temp;
                flag = 0;   
            }
            t = t->next;
            p = t->next;
            q = p->next;
        }
        if(flag)
            break;
    }
    free(head_front);  //排序完成后释放掉内存
}

The above code can only be achieved on a small element of the second list of elements than the sort studied for a long time, I do not know why, and so then I came back to find out the modification;

The complete code

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

typedef struct student
{
    int num;
    char name;
    struct student *next;
    
}STUDENT;

STUDENT *head;
int sum;

void create(){
    int num1;
    char name1;
    STUDENT *p_end=NULL,*p_new;
    int i=0;
    printf("请输入元素个数:");
    scanf("%d",&sum);
    for(int t=0;t<sum;t++)
    {
        printf("第%d个学生信息:",++i);
        scanf("%d %c",&num1,&name1);
        if(getchar()=='%')
            break;
        p_new=(STUDENT *)malloc(sizeof(STUDENT));
        if(p_new==NULL)
            exit(0);
        if(i==1)
        {
            p_new->name=name1;
            p_new->num=num1;
            head=p_new;
            p_end=p_new;
        }
        else
        {
        p_new->name=name1;
        p_new->num=num1;
        p_end->next=p_new;
        p_new->next=NULL;
        p_end=p_new;
       
       }
    }
}
void swap(){
    STUDENT *head_front ;
    head_front=(STUDENT *)malloc(sizeof(STUDENT));
    head_front->next=head;
    STUDENT *t, *p,*q,*temp;
    for(int i=0;i<sum+1;i++)
    {
        int flag = 1;
        t=head_front;
        p=t->next;
        q=p->next;
        for(int j=0;j<sum-i-1;j++)
        {
            if(p->num > q->num)
            {
                t->next = q;
                p->next = q->next;
                q->next = p;
                
                temp = p; p = q;q = temp;
               flag = 0;
                
            }
            t = t->next;
            p = t->next;
            q = p->next;
        }
        if(flag)
            break;
    }
    free(head_front);
}

void output()
{
    STUDENT *p;
    p=head;
    for(int i=0;i<sum;i++)
    {
        printf("%d %c \n",p->num, p->name);
        p=p->next;
    }
    printf("\n");
}

int main()
{
    head=NULL;
    create();
    swap();
    output();
}