Programmer Think

1. Fiborachi thinking (1) dp[i] Fibolacci number i, I is the number I I (2) Recursive formula dp[i]=dp[i-1]+dp[i+1] 3. Initialize the first two 0 and 1 (4) Traversal order is from front to back Examples The problem here is that the value is too large and requires redundancy of 1000000007. class Solution { public int fib(int n) { ...

Problem description and status definition Digital triangle problem. There is a triangle composed of non negative integers. There is only one number in the first row. Except for the lowest row, there are one number at the lower left and right of each number, as shown in the figure. Starting from the number in the first line, you can go dow ...

1. Background requirements: We have three kinds of coins with different denominations, 11 yuan, 5 yuan and 1 yuan (there must be). We have to pay 15 yuan (integer). How many coins do we need at least? At least 3 coins (3 5 yuan coins). 2. Realization of dynamic programming This problem should be fully suitable for dynamic programming ...

1. Question 5 of the longest palindrome substring force deduction Substring: substring must be continuous, which is different from the concept of subsequence Subsequence: Where the violent solution can be optimized: palindromes are judged only when the length of the substring is > the current maximum length, Is there anything that can be ...