Prime Number
Intro Approach 1 gives the method to test whether n is a prime number.
LeetCode 204.
Intuition On first glimpse, I try DP and turn out TLE, shit again.
LeetCode 278.
Intuition Binary Seaching to find the answer
LeetCode 1482.
Intuition I use dynamic programming on my first thought. It works but turns out to be TLE.
LeetCode 633.
Intuition a^2 + b^2 = c; (a >= 0 & b >= 0 & a,b,c are integers)