C ++程序在二叉树中查找最深的左叶

Z时代
2024-01-10
分类：综合

具有最多两个子代的二叉树，分别指定为左子代和右子代。这是一个C ++程序，用于查找二叉树中最深的左叶

算法

Begin.

function deepestLLeafutil() find the deepest left leaf in a given

binary tree:

lvel is level of current node.

maxlvel is pointer to the deepest left leaf node found so far

isLeft Indicates that this node is left child of its parent

resPtr is Pointer to the result

If root is equal to Null then

Return.

Update result if this node is having a left leaf and its level is

more than the max level of the current result.

Recursively call function deepestLLeafutil() for left and right subtrees.

End.

范例程式码

#include <iostream>
using namespace std;
struct n {
   int v;
   n *l, *r;
};
void deepestLLeafutil(n *root, int lvel, int *maxvel, bool isLeft, n **resPtr) {
   if (root == NULL)
      return;
   if (isLeft && !root->l && !root->r && lvel > *maxvel) {
      *resPtr = root;
      *maxvel = lvel;
      return;
   }
   deepestLLeafutil(root->l, lvel + 1, maxvel, true, resPtr);
   deepestLLeafutil(root->r, lvel + 1, maxvel, false, resPtr);
}
n* deepestLLeaf( n *root) {
   int maxlevel = 0;
   n *res = NULL;
   deepestLLeafutil(root, 0, &maxlevel, false, &res);
   return res;
}
n *newnode(int d) {
   n *t = new n;
   t->v = d;
   t->l = t->r = NULL;
   return t;
}
int main() {
   n* root = newnode(9);
   root->l = newnode(7);
   root->r = newnode(10);
   root->l->l = newnode(6);
   root->r->l= newnode(8);
   root->r->r = newnode(19);
   root->r->l->r = newnode(4);
   root->r->r->r = newnode(20);
   n *res = deepestLLeaf(root);
   if (res)
      cout << "The deepest left leaf is " << res->v;
   else
      cout << "There is no left leaf in the given tree";
   return 0;
}