dp(i, j) that returns a set of all possible results for the sub-expression from s[i] to s[j].\n2. Use memoization to store the results of sub-expressions to avoid redundant calculations.\n3. For each sub-expression, consider every operator as the potential last operator to be applied and combine the results from the left and right parts accordingly.\n4. Ensure that the results are within the range [0, 1000] as per the constraints.\n5. Calculate the correct result of the expression by following the specified order of operations.\n6. Iterate through the student answers and assign points: 5 points for the correct answer, 2 points for a possible but incorrectly ordered answer, and 0 points otherwise.\n7. Sum up the points for all students and return the total.