func pre2stuf(exps []string) (exps2 []string) {
st1 := stack.NewStack()
st2 := stack.NewStack()
for _, exp := range exps {
if isOperate(exp) {
if op, ok := isPop(st1, exp); ok {
for _, s := range op {
st2.Push(s)
}
}
if exp == ")" {
continue
}
st1.Push(exp)
} else {
st2.Push(exp)
}
}
// fmt.Print(cur.Value)
for !st1.IsEmpty() {
st2.Push(st1.Pop().Value)
}
for _, e := range st2.Elements {
s, _ := e.Value.(string)
exps2 = append(exps2, s)
}
// fmt.Println(exps2)
return
}
func CreateExpressionTree(exps []string) Node {
st := stack.NewStack()
for _, s := range exps {
if isOperate(s) {
operateNode := CreateOperateNode(s)
right, _ := st.Pop().Value.(Node)
left, _ := st.Pop().Value.(Node)
operateNode.setRight(right)
operateNode.setLeft(left)
// fmt.Println(operateNode)
st.Push(operateNode)
} else {
num, _ := strconv.Atoi(s)
numberNode := CreateNumberNode(num)
st.Push(numberNode)
}
}
if st.Len() != 1 {
panic("CreateExpressionTree error")
}
node, _ := st.Pop().Value.(Node)
// fmt.Println(node)
return node
}