GATEverse
← GATE CSE 2026 Set 2

Q29

MCQ2 marks, −0.67

Consider a table TT, where the elements T[i][j],0≤i,j≤nT[i][j], 0 \leq i, j \leq n, represent the cost of the optimal solutions of different subproblems of a problem that is being solved using a dynamic programming algorithm. The recursive formulation to compute the table entries is as follows:

T[0][k]=T[k][0]=1 for k=0,1,2,…,nT[i][j]=2T[i−1][j]+3T[i][j−1] for 1≤i,j≤n\begin{array}{ll} T[0][k]=T[k][0]=1 & \text { for } k=0,1,2, \ldots, n \\ T[i][j]=2 T[i-1][j]+3 T[i][j-1] & \text { for } 1 \leq i, j \leq n \end{array}

Consider the following two algorithms to compute entries of TT. Assume that for both the algorithms, for all 0≤i,j≤n,T[i][j]0 \leq i, j \leq n, T[i][j] has been initialized to 11. Algorithm B1B_{1} : For i=1,2,…,ni=1,2, \ldots, n

 For j=1,2,…,nT[i][j]=2T[i−1][j]+3T[i][j−1]\begin{array}{l} \text { For } j=1,2, \ldots, n \\ \qquad T[i][j]=2 T[i-1][j]+3 T[i][j-1] \end{array}

Algorithm B2:B_{2}: For s=2,3,…,2ns=2,3, \ldots, 2 n

 For i=1,2,…,n For j=1,2,…,n If (i+j==s)T[i][j]=2T[i−1][j]+3T[i][j−1]\begin{array}{l} \text { For } i=1,2, \ldots, n \\ \qquad \begin{array}{l} \text { For } j=1,2, \ldots, n \\ \qquad \text { If }(i+j==s) \\ \quad\quad\quad\quad T[i][j]=2 T[i-1][j]+3 T[i][j-1] \end{array} \end{array}

Algorithm Bk,k∈{1,2}B_{k}, k \in\{1,2\} is said to be correct if and only if it calculates the correct values of T[i][j]T[i][j], for all 0≤i,j≤n0 \leq i, j \leq n, (as per the recursive formulation) at the end of the execution of the algorithm BkB_{k}. Which one of the following statements is true?

Sign in to save attempts.

Loading…