求二叉树中节点的最大距离的C程序实现代码

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

typedef struct Node
{
    char value;
    struct Node *leftChild;
    struct Node *rightChild;
    int maxLeft;//本节点到左子树所有节点的最大距离
    int maxRight;//本节点到右子树所有节点的最大距离
}TreeNode;

int maxLength=0;

//根据中序和前序序列构造二叉树
TreeNode *CreateFromMidPre(char mid[],int midLeft,int midRight,char pre[],int preLeft,int preRight)
{
    TreeNode *node = (TreeNode*)malloc(sizeof(TreeNode));
    int midLeft1,midRight1,preLeft1,preRight1,rootPos=0;

    if(midRight-midLeft != preRight-preLeft)
    {
        printf("错误：输入的中序和前序序列结点个数不一样！\n");
        return node;
    }

    node->value = pre[preLeft];
    node->leftChild = NULL;
    node->rightChild = NULL;
    for(;mid[rootPos]!=pre[preLeft];rootPos++);

    if(rootPos!=midLeft)
    {
        midRight1 = rootPos-1;
        preRight1 = rootPos-midLeft+preLeft;
        node->leftChild = CreateFromMidPre(mid,midLeft,midRight1,pre,preLeft+1,preRight1);
    }
    if(rootPos!=midRight)
    {
        midLeft1 = rootPos+1;
        preLeft1 = rootPos-midLeft+preLeft+1;
        node->rightChild = CreateFromMidPre(mid,midLeft1,midRight,pre,preLeft1,preRight);
    }

    return node;
}

void FindMax(TreeNode *pTree)
{
    if(pTree->leftChild==NULL)
        pTree->maxLeft=0;
    else
    {

        FindMax(pTree->leftChild);

//某节点到左子树的所有节点的最大距离为左子树到其两个子树所有节点最大距离较大的加一

        pTree->maxLeft=(pTree->leftChild->maxLeft > pTree->leftChild->maxRight?pTree->leftChild->maxLeft:pTree->leftChild->maxRight)+1;
    }
    if(pTree->rightChild==NULL)
        pTree->maxRight=0;
    else

    {

        FindMax(pTree->rightChild);

//某节点到右子树的所有节点的最大距离为右子树到其两个子树所有节点最大距离较大的加一

        pTree->maxRight=(pTree->rightChild->maxLeft > pTree->rightChild->maxRight?pTree->rightChild->maxLeft:pTree->rightChild->maxRight)+1;
    }
    
    if(maxLength<pTree->maxLeft+pTree->maxRight)
        maxLength=pTree->maxLeft+pTree->maxRight;
}


int main()
{
    TreeNode *root1;
    char preSeq[20],midSeq[20];
    int i=0,numNode;
    
    printf("请输入节点总数：\n");
    scanf("%d",&numNode);
    fflush(stdin);

    printf("请输入先序序列：\n");
    for(i=0;i<numNode;i++)
        scanf("%c",preSeq+i);
    fflush(stdin);

    printf("请输入中序序列：\n");
    for(i=0;i<numNode;i++)
        scanf("%c",midSeq+i);
    fflush(stdin);

    root1=CreateFromMidPre(midSeq,0,i-1,preSeq,0,i-1);
    FindMax(root1);
    printf("最远的两个节点距离为：%d\n",maxLength);

    return 1;
}