zoukankan      html  css  js  c++  java
  • Nested List Weight Sum II

    Given a nested list of integers, return the sum of all integers in the list weighted by their depth.

    Each element is either an integer, or a list -- whose elements may also be integers or other lists.

    Different from the previous question where weight is increasing from root to leaf, now the weight is defined from bottom up. i.e., the leaf level integers have weight 1, and the root level integers have the largest weight.

    Example 1:
    Given the list [[1,1],2,[1,1]], return 8. (four 1's at depth 1, one 2 at depth 2)

    Example 2:
    Given the list [1,[4,[6]]], return 17. (one 1 at depth 3, one 4 at depth 2, and one 6 at depth 1; 1*3 + 4*2 + 6*1 = 17)

     1 /**
     2  * // This is the interface that allows for creating nested lists.
     3  * // You should not implement it, or speculate about its implementation
     4  * public interface NestedInteger {
     5  *     // Constructor initializes an empty nested list.
     6  *     public NestedInteger();
     7  *
     8  *     // Constructor initializes a single integer.
     9  *     public NestedInteger(int value);
    10  *
    11  *     // @return true if this NestedInteger holds a single integer, rather than a nested list.
    12  *     public boolean isInteger();
    13  *
    14  *     // @return the single integer that this NestedInteger holds, if it holds a single integer
    15  *     // Return null if this NestedInteger holds a nested list
    16  *     public Integer getInteger();
    17  *
    18  *     // Set this NestedInteger to hold a single integer.
    19  *     public void setInteger(int value);
    20  *
    21  *     // Set this NestedInteger to hold a nested list and adds a nested integer to it.
    22  *     public void add(NestedInteger ni);
    23  *
    24  *     // @return the nested list that this NestedInteger holds, if it holds a nested list
    25  *     // Return null if this NestedInteger holds a single integer
    26  *     public List<NestedInteger> getList();
    27  * }
    28  */
    29 public class Solution {
    30     public int depthSumInverse(List<NestedInteger> nestedList) {
    31         return helper(nestedList, 0);
    32     }
    33     
    34     private int helper(List<NestedInteger> nestedList, int pre) {
    35         if (nestedList.isEmpty()) return 0;
    36         
    37         int unwighted = pre, wighted = 0;
    38         List<NestedInteger> next = new ArrayList<>();
    39         
    40         for (NestedInteger temp : nestedList) {
    41             if (temp.isInteger())
    42                 unwighted += temp.getInteger();
    43             else
    44                 next.addAll(temp.getList());
    45         }
    46         
    47         wighted = next.isEmpty() ? 0 : helper(next, unwighted);
    48         return wighted + unwighted;
    49     }
    50 }
  • 相关阅读:
    89组合margin、padding、float、clear问题
    absoulue与relative配合定位盒子居中问题
    11种常用css样式之表格和定位样式学习
    11种常用css样式之鼠标、列表和尺寸样式学习
    C++走向远洋——54(项目一2、分数类的重载、取倒数)
    C++走向远洋——53(项目一1、分数类的重载、加减乘除、比较)
    HTML标签学习总结(1)
    9——PHP循环结构foreach用法
    C++走向远洋——52(十三周阅读程序)
    我为什么要用CSDN博客?
  • 原文地址:https://www.cnblogs.com/amazingzoe/p/6412038.html
Copyright © 2011-2022 走看看