NC_62_IS_BALANCED NC_63_IS_Continuous NC_66_FindFirstCommonNode

package org.example.interview.practice;

/**
 * @author xianzhe.ma
 * @date 2021/8/15
 */

public class NC_62_IS_BALANCED {
    public boolean IsBalanced_Solution(TreeNode root) {
        if (root == null) {
            return true;
        }
        if (!IsBalanced_Solution(root.left)) {
            return false;
        }

        if (!IsBalanced_Solution(root.right)) {
            return false;
        }

        return Math.abs(deep(root.left) - deep(root.right)) <= 1;

    }

    public int deep(TreeNode node) {
        if (node == null) {
            return 0;
        }

        int leftDeep = deep(node.left);

        int rightDeep = deep(node.right);

        return Math.max(leftDeep, rightDeep) + 1;
    }


      public class TreeNode {
        int val = 0;
        TreeNode left = null;
        TreeNode right = null;
      }

}

package org.example.interview.practice;

import java.util.Arrays;

/**
 * @author xianzhe.ma
 * @date 2021/8/22
 */

public class NC_63_IS_Continuous {
    public boolean IsContinuous(int [] numbers) {

        Arrays.sort(numbers);

        int max = numbers[4];
        int min = numbers[0];

        if (min == 0) {
            int zeroNum = 0;
            for (int i=0;i<4;i++) {
                if (numbers[i] == 0) {
                    zeroNum++;
                }
            }

            for (int j = 3; j >= 0; j--) {
                if (numbers[j] != max-(4-j) ) {
                    if (zeroNum <= 0) {
                        return  false;
                    } else {
                        zeroNum--;
                        numbers[0] = max-(4-j);
                        Arrays.sort(numbers);
                    }
                }
            }

        } else {
            for (int j = 3; j >= 0; j--) {
                if (numbers[j] != max-(4-j)) {
                    return false;
                }
            }
        }

        return true;
    }
}

package org.example.interview.practice;

/**
 * @author xianzhe.ma
 * @date 2021/11/3
 */

public class NC_66_FindFirstCommonNode {

    public ListNode FindFirstCommonNode(ListNode pHead1, ListNode pHead2) {

        ListNode l1 = pHead1, l2 = pHead2;

        while (l1 != l2) {
            l1 = (l1 == null) ? pHead2 : l1.next;
            l2 = (l2 == null) ? pHead1 : l2.next;
        }

        return l1;
    }

    public static class ListNode {
        int val;
        ListNode next = null;

        public ListNode(int val) {
            this.val = val;
        }
    }
}

 

public class NC_68_JUMPFLOOR{
    public int jumpFloor(int target) {
        
        if (target == 0) {
            return 1;    
        }
        
        if (target == 1) {
            return 1;
        }
        
        return jumpFloor(target - 1) + jumpFloor(target - 2);
    }
}