What cycles should be inside a stepped array to find rows with the same elements?

Question

C++ / C#

// 7. Print the numbers of those rows of the stepped array, **
// which consist of the same elements.
I generated a jagged array and gave each cell a value.
Now the main question is how to find lines with the same elements in cycles and not only to me. I

got to this, but I don’t understand further. What to fix and how to proceed