Question

Hello, I need help with my code. The code needs to display random number from 1 to 50 every time the program runs but the program displays the same random numbers every time. Thanks

#include

#include

using namespace std;

void dynAlloc(int size, int *&arr);

void displayArray(int *arr, int n);

void insertionSort(int *arr, int n, int *temp);

void linear_search(int *arr, int n, int key);

void binary_search(int *arr, int n, int key);

int main() {  

const int n = 50;

int *arr, *temp;

dynAlloc(n, arr);

dynAlloc(n, temp);

// randomly generating 50 numbers

for (int i = 0; i < n; i++)

arr[i] = (rand() % 100) + 1;

cout << "\nHere is the unsorted array" << endl;

displayArray(arr, n);

insertionSort(arr, n, temp);

cout << "\nHere is the sorted array" << endl;

displayArray(temp, n);

int key;

cout << "\nEnter an integer to search for" << endl;

cin >> key;

while (key != -1) {

linear_search(arr, n, key);

binary_search(temp, n, key);

cout << "\nEnter an integer to search for" << endl;

cin >> key;

}

cout << "Thanks and have a nice day!" << endl;

delete arr;

delete temp;

return 0;

}

void dynAlloc(int size, int *&arr) { arr = new int[size]; }  

void displayArray(int *arr, int n) {

for (int i = 0; i < n; i++) {

cout << arr[i] << " ";

if ((i + 1) % 5 == 0)

cout << endl;

}

cout << endl;

}

void insertionSort(int *arr, int n, int *temp) {

for (int i = 0; i < n; i++)

temp[i] = arr[i];

for (int i = 0; i < n; i++) {

for (int j = i + 1; j < n; j++) {

if (temp[i] > temp[j]) {

int t = temp[i];

temp[i] = temp[j];

temp[j] = t;

}

}

}

}

void linear_search(int *arr, int n, int key) {

cout << "invoking linear search" << endl;

int i;

for (i = 0; i < n; i++) {

if (arr[i] == key) {

cout << "target found - element # " << i << endl;

break;

}

}

cout << "number of iterations = " << i << endl;

}

void binary_search(int *arr, int n, int key) {

cout << "invoking binary search" << endl;

int l = 0;

int r = n - 1;

int i = 0;

bool isFound = false;

while (l <= r) {

int m = l + (r - l) / 2;

if (arr[m] == key) {

cout << "target found - element # " << m << endl;

isFound = true;

break;

} else if (arr[m] < key)

l = m + 1;

else

r = m - 1;

i++;

}

if (!isFound)

cout << "target not found" << endl;

cout << "number of iterations = " << i << endl;

}

Display of numbers 1:

Here is the unsorted array

8 50 74 59 31

73 45 79 24 10

41 66 93 43 88

4 28 30 41 13

4 70 10 58 61

34 100 79 17 36

98 27 13 68 11

34 80 50 80 22

68 73 94 37 86

46 29 92 95 58

Here is the sorted array

4 4 8 10 10

11 13 13 17 22

24 27 28 29 30

31 34 34 36 37

41 41 43 45 46

50 50 58 58 59

61 66 68 68 70

73 73 74 79 79

80 80 86 88 92

93 94 95 98 100

Display of numbers 2:

Here is the unsorted array

8 50 74 59 31

73 45 79 24 10

41 66 93 43 88

4 28 30 41 13

4 70 10 58 61

34 100 79 17 36

98 27 13 68 11

34 80 50 80 22

68 73 94 37 86

46 29 92 95 58

Here is the sorted array

4 4 8 10 10

11 13 13 17 22

24 27 28 29 30

31 34 34 36 37

41 41 43 45 46

50 50 58 58 59

61 66 68 68 70

73 73 74 79 79

80 80 86 88 92

93 94 95 98 100

Enter an integer to search for

Answer 1

Code - You have to add  srand(time(0)); before storing random number in array because what srand(time(0));
does is it Uses current time for generating random number , so every time you run you will generate new random number , I have this in code you can try running the code.

#include <iostream>

using namespace std;

void dynAlloc(int size, int *&arr);

void displayArray(int *arr, int n);

void insertionSort(int *arr, int n, int *temp);

void linear_search(int *arr, int n, int key);

void binary_search(int *arr, int n, int key);

int main() {

const int n = 50;

int *arr, *temp;

dynAlloc(n, arr);

dynAlloc(n, temp);

// randomly generating 50 numbers
//Usin current time for generating random time , so every time you run you will generate new random number
srand(time(0));

for (int i = 0; i < n; i++)

arr[i] = (rand() % 100) + 1;

cout << "\nHere is the unsorted array" << endl;

displayArray(arr, n);

insertionSort(arr, n, temp);

cout << "\nHere is the sorted array" << endl;

displayArray(temp, n);

int key;

cout << "\nEnter an integer to search for" << endl;

cin >> key;

while (key != -1) {

linear_search(arr, n, key);

binary_search(temp, n, key);

cout << "\nEnter an integer to search for" << endl;

cin >> key;

}

cout << "Thanks and have a nice day!" << endl;

delete arr;

delete temp;

return 0;

}

void dynAlloc(int size, int *&arr) { arr = new int[size]; }

void displayArray(int *arr, int n) {

for (int i = 0; i < n; i++) {

cout << arr[i] << " ";

if ((i + 1) % 5 == 0)

cout << endl;

}

cout << endl;

}

void insertionSort(int *arr, int n, int *temp) {

for (int i = 0; i < n; i++)

temp[i] = arr[i];

for (int i = 0; i < n; i++) {

for (int j = i + 1; j < n; j++) {

if (temp[i] > temp[j]) {

int t = temp[i];

temp[i] = temp[j];

temp[j] = t;

}

}

}

}

void linear_search(int *arr, int n, int key) {

cout << "invoking linear search" << endl;

int i;

for (i = 0; i < n; i++) {

if (arr[i] == key) {

cout << "target found - element # " << i << endl;

break;

}

}

cout << "number of iterations = " << i << endl;

}

void binary_search(int *arr, int n, int key) {

cout << "invoking binary search" << endl;

int l = 0;

int r = n - 1;

int i = 0;

bool isFound = false;

while (l <= r) {

int m = l + (r - l) / 2;

if (arr[m] == key) {

cout << "target found - element # " << m << endl;

isFound = true;

break;

} else if (arr[m] < key)

l = m + 1;

else

r = m - 1;

i++;

}

if (!isFound)

cout << "target not found" << endl;

cout << "number of iterations = " << i << endl;

}

Screenshots -

First run -

Second Run -

Pls do give a like , thank you . If you have any question pls ask in comment section