diff --git a/Chainlist_program.c b/Chainlist_program.c
new file mode 100644
index 0000000..b668814
--- /dev/null
+++ b/Chainlist_program.c
@@ -0,0 +1,292 @@
+#include <stdio.h>
+#include <malloc.h>
+#include <stdbool.h>
+#include <string.h>
+#include <windows.h>
+
+typedef struct Student
+{
+    char id[20];
+    char class[20];
+    char name[20];
+    double score1;
+    double score2;
+    double score3;
+    double score;
+
+    struct Student *prev;
+    struct Student *next;
+}LinkList;
+
+bool sorted=false;
+
+typedef bool (*Linklist_cmp)(LinkList *,LinkList *);
+
+bool bigger(LinkList * a,LinkList * b){
+    return a->score<b->score;
+}
+
+bool smallerclass_biggerscore(LinkList * a,LinkList * b){
+    if(strcmp(a->class,b->class)>0){
+        return 1;
+    }
+    else if(strcmp(a->class,b->class)==0) {
+        return a->score<b->score;
+    }
+    return 0;
+}
+
+LinkList *Linklist_append(LinkList  *prev) {
+    LinkList *node;
+    node = (LinkList *) malloc(sizeof(LinkList));
+
+    printf("Id ");
+    scanf("%s",node->id);
+    printf("class ");
+    scanf("%s",node->class);
+    printf("name ");
+    scanf("%s",node->name);
+    printf("score1 ");
+    scanf("%lf",&node->score1);
+    printf("score2 ");
+    scanf("%lf",&node->score2);
+    printf("score3 ");
+    scanf("%lf",&node->score3);
+
+    node->score = node->score1 + node->score2 + node->score3;
+
+    prev->next=node;
+    node->next=NULL;
+    node->prev=prev;
+
+    return node;
+}
+
+void Linklist_delete(LinkList  *cur) {
+
+    if(cur->next != NULL){
+        cur->next->prev=cur->prev;
+    }
+    cur->prev->next=cur->next;
+}
+
+void Linklist_swap(LinkList *s1, LinkList *s2){
+    if(s1->next == s2){
+        if(s2->next != NULL){
+            s2->next->prev = s1;
+        }
+        if(s1->prev != NULL){
+            s1->prev->next = s2;
+        }
+        s1->next = s2->next;
+        s2->prev = s1->prev;
+        s1->prev = s2;
+        s2->next = s1;
+    }else if(s1->prev == s2){
+        if(s1->next != NULL){
+            s1->next->prev = s2;
+        }
+        if(s2->prev != NULL){
+            s2->prev->next = s1;
+        }
+        s2->next = s1->next;
+        s1->prev = s2->prev;
+        s2->prev = s1;
+        s1->next = s2;
+    }else{
+        if(s1->next != NULL){
+            s1->next->prev = s2;
+        }
+        if(s1->prev != NULL){
+            s1->prev->next = s2;
+        }
+        if(s2->next != NULL){
+            s2->next->prev = s1;
+        }
+        if(s2->prev != NULL){
+            s2->prev->next = s1;
+        }
+        LinkList *s1Next = s1->next;
+        LinkList *s1prev = s1->prev;
+        s1->next = s2->next;
+        s1->prev = s2->prev;
+        s2->next = s1Next;
+        s2->prev = s1prev;
+    }
+}
+
+void Linklist_Sort(LinkList *p,Linklist_cmp cmp){
+    LinkList *head = p;
+    while(head != NULL){
+        LinkList *headNext = head->next;
+        while(headNext != NULL){
+            if(cmp(head, headNext)){
+                Linklist_swap(head, headNext);
+//注意这里一定要交换下，因为改了链表节点的位置
+                LinkList *tmp = head;
+                head = headNext;
+                headNext = tmp;
+            }
+            headNext = headNext->next;
+        }
+        head = head->next;
+    }
+}
+void find_delete(LinkList * head){
+    char todelatte[20];
+    scanf("%s",todelatte);
+    LinkList * node_ptr;
+    node_ptr = head;
+    while (node_ptr->next != NULL) {
+        node_ptr = node_ptr->next;
+        if(strcmp(todelatte,node_ptr->id)==0 || strcmp(todelatte,node_ptr->name)==0) {
+            Linklist_delete(node_ptr);
+            break;
+        }
+    }
+    Linklist_Sort(head->next,bigger);
+    node_ptr=head;
+    while(node_ptr->next != NULL){
+        node_ptr = node_ptr->next;
+        printf("%s,%s,%s,%lf,%lf,%lf,%lf\n",node_ptr->id,node_ptr->class,node_ptr->name,node_ptr->score1,node_ptr->score2,node_ptr->score3,node_ptr->score);
+    }
+}
+
+void find(LinkList * head){
+    char todelatte[20];
+    scanf("%s",todelatte);
+    LinkList * node_ptr;
+    node_ptr = head;
+    bool find_flag=false;
+    while (node_ptr->next != NULL) {
+        node_ptr = node_ptr->next;
+        if(strcmp(todelatte,node_ptr->id)==0 || strcmp(todelatte,node_ptr->class)==0) {
+            printf("%s,%s,%s,%lf,%lf,%lf,%lf\n",node_ptr->id,node_ptr->class,node_ptr->name,node_ptr->score1,node_ptr->score2,node_ptr->score3,node_ptr->score);
+            find_flag = true;
+        }
+    }
+    if(!find_flag)printf("there is no eligible student\n");
+}
+
+void sort_output(LinkList * head){
+    Linklist_Sort(head,smallerclass_biggerscore);//
+    LinkList * node_ptr=head;
+    while(node_ptr->next != NULL){
+        node_ptr = node_ptr->next;
+        printf("%s,%s,%s,%lf,%lf,%lf,%lf\n",node_ptr->id,node_ptr->class,node_ptr->name,node_ptr->score1,node_ptr->score2,node_ptr->score3,node_ptr->score);
+    }
+}
+
+void output(LinkList * head){
+    if(sorted)Linklist_Sort(head,smallerclass_biggerscore);
+    LinkList * node_ptr=head;
+    while(node_ptr->next != NULL){
+        node_ptr = node_ptr->next;
+        printf("%s,%s,%s,%lf,%lf,%lf,%lf\n",node_ptr->id,node_ptr->class,node_ptr->name,node_ptr->score1,node_ptr->score2,node_ptr->score3,node_ptr->score);
+    }
+}
+
+void print_options(){
+    printf("1.input\n");
+    printf("2.delete\n");
+    printf("3.select\n");
+    printf("4.order\n");
+    printf("5.output\n");
+    printf("6.quit\n");
+    printf("please input your option\n");
+}
+
+int main(void) {
+    LinkList *head,*cur_node;//定义头节点，普通节点，尾部节点；
+    head = (LinkList*)malloc(sizeof(LinkList));//分配地址
+    head->prev=NULL;
+
+
+    LinkList wang={"1003","11","wang",1,2,3,6,head,NULL};
+    LinkList zhang={"1002","22","zhang",3,2,3,8,&wang,NULL};
+    LinkList li={"1001","11","li",1,4,3,9,&zhang,NULL};
+    head->next=&wang;
+    wang.next=&zhang;
+    zhang.next= &li;
+
+
+
+    while(1){
+        print_options();
+        rewind(stdin);
+        int op = getchar();
+        switch(op){
+            case '1':{
+                cur_node = Linklist_append(head);
+                printf("\r\ncontinue?\r\n");
+                rewind(stdin);
+                int yn = getchar();
+                while(yn != 'n'){
+                    cur_node = Linklist_append(cur_node);
+                    printf("\r\ncontinue?\r\n");
+                    rewind(stdin);
+                    yn=getchar();
+                }
+                break;
+            }
+            case '2':{
+                find_delete(head);
+                printf("\r\ncontinue?\r\n");
+                rewind(stdin);
+                int yn = getchar();
+                while(yn != 'n'){
+                    find_delete(head);
+                    printf("\r\ncontinue?\r\n");
+                    rewind(stdin);
+                    yn=getchar();
+                }
+                break;
+            }
+            case '3':{
+                find(head);
+                printf("\r\ncontinue?\r\n");
+                rewind(stdin);
+                int yn = getchar();
+                while(yn != 'n'){
+                    find(head);
+                    printf("\r\ncontinue?\r\n");
+                    rewind(stdin);
+                    yn=getchar();
+                }
+                break;
+            }
+            case '4':{
+                ///make sure to run this code under ucrt64 but not mingw64!
+                sort_output(head);
+                printf("\r\ncontinue?\r\n");
+                rewind(stdin);
+                int yn = getchar();
+                while(yn != 'n'){
+                    sort_output(head);
+                    printf("\r\ncontinue?\r\n");
+                    rewind(stdin);
+                    yn=getchar();
+                }
+                sorted = true;
+                break;
+            }
+            case '5':{
+                output(head);
+                printf("\r\ncontinue?\r\n");
+                rewind(stdin);
+                int yn = getchar();
+                while(yn != 'n'){
+                    output(head);
+                    printf("\r\ncontinue?\r\n");
+                    rewind(stdin);
+                    yn=getchar();
+                }
+                break;
+            }
+            default:{
+                return 0;
+            }
+
+        }
+    }
+}