FilesExpand file tree

 master

/

339_NestedListWeightSum339.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

66 lines (62 loc) · 2.08 KB

 master

/

339_NestedListWeightSum339.java

Copy path

Top

File metadata and controls

• Code
• Blame

66 lines (62 loc) · 2.08 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

/**

* 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.

*

* Example 1:

* Input: [[1,1],2,[1,1]]

* Output: 10

* Explanation: Four 1's at depth 2, one 2 at depth 1.

*

* Example 2:

* Input: [1,[4,[6]]]

* Output: 27

* Explanation: One 1 at depth 1, one 4 at depth 2, and one 6 at depth 3;

* 1 + 4*2 + 6*3 = 27.

*/

/**

* // This is the interface that allows for creating nested lists.

* // You should not implement it, or speculate about its implementation

* public interface NestedInteger {

* // Constructor initializes an empty nested list.

* public NestedInteger();

*

* // Constructor initializes a single integer.

* public NestedInteger(int value);

*

* // @return true if this NestedInteger holds a single integer, rather than a nested list.

* public boolean isInteger();

*

* // @return the single integer that this NestedInteger holds, if it holds a single integer

* // Return null if this NestedInteger holds a nested list

* public Integer getInteger();

*

* // Set this NestedInteger to hold a single integer.

* public void setInteger(int value);

*

* // Set this NestedInteger to hold a nested list and adds a nested integer to it.

* public void add(NestedInteger ni);

*

* // @return the nested list that this NestedInteger holds, if it holds a nested list

* // Return null if this NestedInteger holds a single integer

* public List<NestedInteger> getList();

* }

*/

public class NestedListWeightSum339 {

public int depthSum(List<NestedInteger> nestedList) {

return depthSum(nestedList, 1);

}

private int depthSum(List<NestedInteger> nestedList, int level) {

int res = 0;

for (NestedInteger ni: nestedList) {

if (ni.isInteger()) {

res += ni.getInteger() * level;

} else {

res += depthSum(ni.getList(), level + 1);

}

}

return res;

}

}