g0301_0400.s0306_additive_number

Class Solution

java.lang.Object

g0301_0400.s0306_additive_number.Solution

public class Solution
extends Object

306 - Additive Number.

Medium

An additive number is a string whose digits can form an additive sequence.

A valid additive sequence should contain at least three numbers. Except for the first two numbers, each subsequent number in the sequence must be the sum of the preceding two.

Given a string containing only digits, return true if it is an additive number or false otherwise.

Note: Numbers in the additive sequence cannot have leading zeros, so sequence 1, 2, 03 or 1, 02, 3 is invalid.

Example 1:

Input: “112358”

Output: true

Explanation:

The digits can form an additive sequence: 1, 1, 2, 3, 5, 8.
1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, 3 + 5 = 8 

Example 2:

Input: “199100199”

Output: true

Explanation:

The additive sequence is: 1, 99, 100, 199.
1 + 99 = 100, 99 + 100 = 199 

Constraints:

• 1 <= num.length <= 35
• num consists only of digits.

Follow up: How would you handle overflow for very large input integers?

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
boolean	isAdditiveNumber(String num)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

isAdditiveNumber

public boolean isAdditiveNumber(String num)