hihocoder 1049 后续遍历

#include<iostream>#include<cstdio>#include<string>#include<cstdlib>#include<string.h>using namespace std;char preorder[30],midorder[30],endorder[30];typedef struct mynode Node;typedef Node* Tree;struct mynode{    char data;    struct mynode* left;    struct mynode* right;};int build(int left,int right,Tree &root)//更新了一下使用引用使结构更加清晰{    if(left>right)        return 0;    int i,j,flag = 1;    for(i=0; i<strlen(preorder); i++)    {        for(j=left; j<=right; j++)            if(preorder[i]==midorder[j])            {                flag = 0;                break;            }        if(!flag)            break;    }    root = (Node*)malloc(sizeof(Node));    if(root==NULL)    {        perror("malloc failed");        exit(1);    }    root->left = NULL;    root->right = NULL;    root->data = preorder[i];    build(left,j-1,root->left);    build(j+1,right,root->right);}void del(Tree root){    if(root!=NULL)    {        del(root->left);        del(root->right);    }    if(root!=NULL)    {        free(root);        root = NULL;    }}int pos = 0;int endcal(Tree root){    if(pos == strlen(preorder))        return 0;    if(root->left)    {        endcal(root->left);    }    if(root->right)    {        endcal(root->right);    }    endorder[pos++] = root->data;}int main(){    Tree root;    cin>>preorder>>midorder;    build(0,strlen(preorder)-1,root);    endcal(root);    cout<<endorder<<endl;    del(root);}

代码可以AC不知道有没有内存泄漏 有错误请指出

下面是别人写的

#include<iostream>#include<cstdio>#include<cstdlib>#include<string.h>using namespace std;char preorder[30],inorder[30],endorder[30];void endcal(const char *pre,const char *in,int len){    if(len<1)        return ;    int i=0;    while(in[i]!=pre[0])i++;    endcal(pre+1,in,i);    endcal(pre+i+1,in+i+1,len-i-1);    cout<<pre[0];}int main(){    cin>>preorder>>inorder;    endcal(preorder,inorder,strlen(preorder));}

顺便给出前序遍历

#include<iostream>#include<cstdio>#include<cstdlib>#include<string.h>using namespace std;char pre[30],in[30],last[30];void precal(char *last,char *in,int lastend,int inend){    if(lastend<0||inend<1)        return ;    int i=0;    while(in[i]!=last[lastend-1])i++;    cout<<last[lastend-1];    precal(last,in,lastend-inend+i,i);    precal(last,in+i+1,lastend-1,inend-i-1);}int main(){    while(cin>>last>>in)        precal(last,in,strlen(last),strlen(in)),putchar('\n');}