Take a look at the triangle on the left of the figure below. It is made of 9 (unit) triangles arranged in three rows (N = 3 ). Needless to say, a unit triangle is a triangle with N = 1 .
If you study the figure for few seconds, you'll realize that you can find 13 different triangles (which we'll call sub-triangles.) Of these 13 sub-triangles we have: Nine unit triangle; three with N = 2 , and one with N = 3 . The following table lists the number of sub-triangles in arrangements with N < 5 .
Let's define the value of a unit triangle to be the integer value written in that triangle. In general, the value of a triangle is the sum of values in all its unit triangles. The triangle on the right is the same as the other one but with the sub-triangle having the largest value being highlighted. Write a program to determine the sub-triangle with the largest value.