03-树3 Tree Traversals Again

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

#define MAXSIZE 30

typedef struct node{
int top;
int cap;
int data[MAXSIZE];
} Stack;

int preOrder[MAXSIZE];
int inOrder[MAXSIZE];
int postOrder[MAXSIZE];

Stack* CreateStack();
void Push(Stack *PtrS, int e);
void Pop(Stack *PtrS);
int Top(Stack *PtrS);
void Solve(int prel, int inl, int postl, int n);

int main(int argc, char const *argv[])
{
for (int i = 0; i < MAXSIZE; ++i){
preOrder[i] = 0;
inOrder[i] = 0;
postOrder[i] = 0;
}
// freopen("test.txt", "r", stdin);
int NodeNum, data;
scanf("%d", &NodeNum);
int perIndex = 0, inIndex = 0, postIndex = 0;
Stack *PS = CreateStack();
Push(PS, 0);
char str[20];
for (int i = 0; i < 2 * NodeNum; ++i){
scanf("%s", str);
if(strcmp(str, "Push") == 0){
scanf("%d", &data);
preOrder[perIndex++] = data;
Push(PS, data);
}
else if(strcmp(str, "Pop") == 0){
inOrder[inIndex++] = Top(PS);
Pop(PS);
}
}
Solve(0, 0, 0, NodeNum);
for (int i = 0; i < NodeNum; ++i){
if(i == NodeNum - 1)
printf("%d", postOrder[i]);
else
printf("%d ", postOrder[i]);
}
return 0;
}

Stack* CreateStack()
{
Stack *PtrS = (Stack*)malloc(sizeof(Stack));
PtrS->cap = MAXSIZE;
PtrS->top = -1;
return PtrS;
}

void Push(Stack *PtrS, int e)
{
if(PtrS->top == PtrS->cap - 1)
return;
PtrS->top++;
PtrS->data[PtrS->top] = e;
}

int Top(Stack *PtrS)
{
if(PtrS->top != -1)
return PtrS->data[PtrS->top];
}

void Pop(Stack *PtrS)
{
if(PtrS->top == -1)
return;
PtrS->top--;
}

void Solve(int prel, int inl, int postl, int n)
{
if(n == 0)
return;
if(n == 1){
postOrder[postl + n -1] = preOrder[prel];
return;
}
int L, R, root;
root = preOrder[prel];
postOrder[postl + n -1] = root;
for (int i = 0; i < n; ++i){
if(inOrder[inl + i] == root){
L = i;//左子树结点个数
R = n - i -1;//右子树结点个数
break;
}
}
Solve(prel+1, inl, postl, L);
Solve(prel+L+1, inl+L+1, postl+L, R);
}