node * dest = NULL;
//找到某一英语成绩所对应的记录的BST节点的父节点 void searParent(BST t, keytype a) {
if(t == NULL) {
parent = NULL; }
else if(a == t ->data.key) {
dest = t; return; } else {
parent = t;
if(a < t->data.key) {
searParent(t->lchild, a); } else {
searParent(t->rchild, a); } } }
//删除以英语成绩为关键字的BST中英语成绩为a的记录 BST dele(BST t, keytype a) {
node * tmp; node * tmp2;
searParent(t, a); if(t == NULL) {
printf(\找不到要删除的记录!\\n\ return t; }
else if( t ->lchild == NULL && t->rchild == NULL) {
free(t);
return NULL; }
else if(parent == NULL)
{
printf(\找不到要删除的记录!\\n\ return t; } else {
if(dest->lchild == NULL && dest ->rchild == NULL) {
tmp = dest;
if(parent ->lchild == dest) {
parent ->lchild =NULL; } else {
parent ->rchild = NULL; }
free(tmp); }
else if(dest ->lchild == NULL) {
tmp = dest; if(dest != t) {
if(parent ->lchild == dest) {
parent ->lchild = dest ->rchild; } else {
parent ->rchild = dest ->rchild; } } else {
t = t ->rchild; }
free(tmp); }
else if(dest -> rchild == NULL) {
tmp = dest; if(dest != t) {
if(parent ->lchild == dest) {
parent ->lchild = dest ->lchild; } else {
t = dest ->lchild; } } else {
t = t ->lchild; }
free(tmp); } else {
tmp2 = dest; parent = dest;
tmp2 = tmp2 -> rchild;
while(tmp2 -> lchild != NULL) {
parent = tmp2;
tmp2 = tmp2 -> lchild; }
dest -> data = tmp2 ->data; if(parent == dest) {
parent ->rchild = tmp2 ->rchild; } else {
parent -> lchild = tmp2-> rchild; }
free(tmp2); }
return t; } }
//根据关键字为记录集排序并输出到屏幕（降序） void sort_output(BST t) {
if(t!= NULL) {
sort_output(t->rchild);
printf(\ printf(\英语：%.1f \ printf(\计算机：%.1f \ printf(\数学：%.1f \ printf(\学分绩：%.1f\\n\ sort_output(t->lchild); } }
//分别建立以英语成绩为关键字的BST和以学分绩为关键字的BST void build2(BST * t, BST * t2) {
record a;
printf(\请依次输入n个记录的姓名 英语成绩 计算机成绩 数学成绩 -1 -1 -1 -1表示结束：\\n\ scanf(\
scanf(\
a.GPA = (a.EN*1.5 + a.CS * 3.5 + a.MATHS * 5)/10; while(a.key!= -1) {
(*t) = inser((*t),a); (*t2) = inser2((*t2), a); scanf(\
scanf(\
a.GPA = (a.EN*1.5 + a.CS * 3.5 + a.MATHS * 5)/10; } }
//在以学分绩为关键字的BST上插入一条记录 BST inser2(BST t, record a) {
if(t == NULL) {
t = malloc(sizeof(node)); t->data= a;
t->lchild = NULL; t->rchild = NULL; } else {
if(a.key2 > t->data.key2)
{
t -> rchild = inser2(t->rchild, a); } else {
if(a.key2 < t->data.key2) {
t ->lchild = inser2(t->lchild, a); } } }
return t; }
//根据学分绩在以学分绩为关键字的BST上查找记录 record sear2(BST t, keytype a) {
record re; re.GPA = -1; if(t == NULL) {
printf(\不存在该关键字所对应的记录！\\n\ return re; }
if(t ->data.key2 == a) {
return t->data; } else {
if(t->data.key2 < a) {
return sear2(t ->rchild, a); } else {
return sear2(t -> lchild, a); } } }
//在以学分绩为关键字的BST上查找学分绩为a的记录对应的结点的父节点 void searParent2(BST t, keytype a) {
if(t == NULL)