摘要：use int[] array , instead of use stringbuilder Because we need to accumulate digits on the same index And the result length is no bigger than n + m th 阅读全文

摘要：This one is very similar to add binary , pretty much the same The only difference is % 10, /10 When the two strings are exhausted, need to check if th 阅读全文

摘要：this one is two strings added together. Still need to add the Two element from two string from the last digit Use a string builder to add backwards, b 阅读全文

摘要：Plus one : so There are a case when the last one is 9, then 1 plus 9 is 0, continue to check if the previous element is 9 or other numbers , if the pr 阅读全文