dp[i][j] = best over split point k of ( dp[i][k] + dp[k+1][j] + cost(i,k,j) ). Watch the table fill diagonal by diagonal and the optimal split k highlight.
[i..j] into [i..k] and [k+1..j];
burst balloons uses the last-element framing with halves (i,k) and (k,j) on the padded array.
The answer is the top-right corner dp[0][n-1]. See junior.md and professional.md for the proof that increasing-length order is a valid topological fill.