bool stuscore::delete_record() {

string s;

student*current,*previous; current=previous=head;

cout<<"成绩表中有"<<length()<<"个学生成绩记录"<<endl; if(!length()) {

cout<<"学生成绩表已空!\n"; return false; } else{

cout<<"请输入要删除的学生记录的学号:" cin>>s; while(current) {

if(current->number==s) {

if(current==head) {

head=head->next; delete current; cout<<"删除成功!"; return true; } else {

previous->next=current->next; delete current; cout<<"删除成功!";