Convert the pre-fix expression to in-fix –* + ABC* – DE + FG
2020
Convert the pre-fix expression to in-fix
–* + ABC* – DE + FG - A.
(A – B)*C + (D*E) – (F + G) - B.
(A + B)*C – (D – E)*(F + G) - C.
(A + B – C)*(D – E))*(F + G) - D.
(A + B)*C – (D*E) – (F + G)
Attempted by 393 students.
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Correct answer: B
To convert prefix to infix, scan right-to-left using a stack. Push operands; when an operator appears, pop two operands and combine as (Operand1 Operator Operand2). For –* + ABC* – DE + FG: 1. Scan G, F: Push G, F. Encounter + → (F + G). 2. Scan E, D: Push E, D. Encounter - → (D - E). 3. Scan *: Combine (D - E) and (F + G) → ((D - E) * (F + G)). 4. Scan C: Push C. 5. Scan B, A: Push B, A. Encounter + → (A + B). 6. Scan *: Combine (A + B) and C → ((A + B) * C). 7. Scan -: Combine the two results → (A + B) * C - (D - E) * (F + G).