Unit 7 - Algorithms

Consider the following code segment. int[] list = { 1, 6, 23, 7, 3, 5, 6 }; int t = 0; for (int i = 0; i < list.length; i++) t = t + list[i]; What is the value of t after this code segment has executed?

Consider the following code segment. int[] list = { 1, 6, 23, 7, 3, 5, 6 }; int t = 0; for (int i = 0; i < list.length; i += 2) t = t + list[i]; What is the value of t after this code segment has executed?

Consider the following code segment. for (int i = 0; i < n; i++) { for (int j = 0; j <= i; j++) { System.out.print(i + " "); } } If the variable n is equal to 4, what is the output?

Consider the following code segment. int a = 18; int b = 42; while (b != 0) { int r = a % b; a = b; b = r; } System.out.println(a); What is printed when this code segment is executed?

Considering the following code segments. I. int a = 1; while (a < 20) { if (a % 4 == 1) { System.out.print(a + " "); } a = a + 4; } II. for (int a = 0; a < 20; a++) { if (a % 4 == 0) { System.out.print(a + " "); } } III. for (int a = 0; a < 20; a = a + 4) { System.out.print(a + " "); } Which of the code segments will output the following? 1 5 9 13 17

Consider the following definition for an array of integers. int[] a = { -4, 32, -13, 32, -10, 17, 22, 21, 30, 24, -5 }; What is stored in a[1]?

Which statement prints the last element in the array?

Consider the following definition for an array of integers. int[] a = { 3, 4, 6463, 4, 7, 8, 5, 3, 2, 3, 6 }; If you were to do a linear search for 7, how many comparisons would be made?

Assuming all variables are declared correctly, which of the following code segments correctly swaps the values x and y? I. x = y; y = x; II. int tmp = x; y = x; x = tmp; III. int tmp = x; x = y; y = tmp;

Consider the following code: int a [] = /* initialization not shown*/; int flag = 0; for (int i = 1; i < a.length; i++) { if (a[i] < a[i-1]) { flag = 1; break; } } What does it do?

The following code is intended to sort an input array of integers into ascending order. int j, k; for (j = a.length - 1; j > 0; j--) { int pos = j; for (/* missing code */) { if (a[k] > a[pos]) { pos = k; } } swap(a, j, pos); } Assume swap(a, j, pos) swaps the values of units j and pos in array a. Which of the following code segments, if replaced for /* missing code */, will make the code run properly?

Consider the following array and method declarations. int[] list = {1, 3, 5, 6, 7, 8, 11, 13, 14, 15, 16, 17, 20, 22, 24, 29, 30, 31, 33, 35}; public static int mystery(int[] a, int s) { for (int i = 0; i < a.length; i++) { if (a[i] == s) { return i; } } return -1; } What would be returned by the following method call? mystery(list,17)?

What operation does the insertion sort use?

For the following array, what is the maximum number of comparisons a linear search will need to do? int[] a= {2, 8, 59, 20, 128, 3, 6, 3, 7, 1};

Consider the array declaration that follows. int[] a = {1, 3, 5, 6, 7, 8, 9, 11, 13, 14, 15}; How many comparisons would it take if you were to search the array for 3 using a binary search?