Additive number is a string whose digits can form 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.For example:"112358" is an additive number because 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"199100199" is also an additive number, the additive sequence is: 1, 99, 100, 199.1 + 99 = 100, 99 + 100 = 199Note: Numbers in the additive sequence cannot have leading zeros, so sequence 1, 2, 03 or 1, 02, 3 is invalid.Given a string containing only digits '0'-'9', write a function to determine if it's an additive number.Follow up:How would you handle overflow for very large input integers?详见:https://leetcode.com/problems/additive-number/description/
C++:
class Solution {public: bool isAdditiveNumber(string num) { for(int i=1;i1&&s1[0]=='0')||(s2.size()>1&&s2[0]=='0')) { continue; } long long next=d1+d2; string nexts=to_string(next); string now=s1+s2+nexts; while(now.size()
参考:https://www.cnblogs.com/grandyang/p/4974115.html