Solution looks like bruteforce with a precalc, not a dynamic programming one. Or precalc counts as DP? Or DP is just a clever bruteforce?

Edited by author 25.07.2017 20:10

Are you calculating something like "maximal sum subarray" ?
That is where it is DP.

If you are doing Kadane algorithm
You are doing essentially that thing

dp[i] = max(0, dp[i-1] + matrix [i])

answer  = max(dp[i])