Every stack is at least one cube high. The front row is at most two high, so the left-column height three must come from the back-left stack. That stack is exactly three high.

For the minimum, the front-right stack can provide height two for both the front row and the right column. Setting the other two stacks to one gives \(1+2+3+1=7\). Fewer cubes cannot supply those two required heights.

For the maximum, each stack can reach its individual limit: front-left two, front-right two, back-left three and back-right two. This gives \(9\) cubes and preserves every stated view.

Answer

Minimum \(7\) cubes: front row \((1,2)\), back row \((3,1)\). Maximum \(9\) cubes: front row \((2,2)\), back row \((3,2)\).