sir I do not understand this line
dp[i][j]=min(dp[ i ] [ j ],
solve_mixtures(i,k)+ solve_mixtures(k+1,j) +sum(i,k)*sum(k+1,j))
Mixtures spoj (DP)
f(i,j) = f(i,k) + f(k+1,j) + csum(i,k)*csum(k+1,j)
See here
Assume
A B C D E
was combined by Harry and finally we have X Y left here X is (A+B+C)%100 and Y is (D+E)%100
Now we combine X & Y we get XY => (A+B+C)%100*(D+E)%100
Correct
No move a step back ,we must have reach to X & Y by solving them individually
So Answer is solve(X)+solve(Y) + XY
This should help