4.5.1-4.5.3 HOW TO SOLVE

 4.5.1
#include <iostream>
#include <stdio.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;

int main() { 

    int n, *arr, onee = 0, twoo, threee, total = 0, maxx = -1, temp_maxx;

    cin >> n;
    arr = new int[n];

    for (int i = 0; i < n; i++) {
        cin >> arr[i];
        total += arr[i];
    }

    // O(n^2) is the following

    for (int i = 1; i < n - 1; i++) {
        onee += arr[i - 1];
        twoo = 0;
        for (int j = i + 1; j < n; j++) {
            twoo += arr[j - 1];
            threee = total - twoo - onee;
            temp_maxx = max(max(onee, twoo), threee);
            if ((temp_maxx < maxx) || (maxx == -1))
                maxx = temp_maxx;
        }
    }

    cout << maxx;

    return 0;
}

4.5.2

var
A; array[1..100] of interger;
i: integer;
begin
for i:=1 to 100 do
begin
A[1]:=i;
end;
End.

4.5.3

#include <iostream>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;

    //Bucket Sort
void bucket_sort (int arr[], int n)
{
  //Here range is [1,100]
  int m = 101;

  //Create m empty buckets
  int buckets[m];

  //Intialize all buckets to 0
  for (int i = 0; i < m; ++i)
    buckets[i] = 0;

  //Increment the number of times each element is present in the input
  //array. Insert them in the buckets
  for (int i = 0; i < n; ++i)
    ++buckets[arr[i]];

  //Sort using insertion sort and concatenate
  for (int i = 0, j = 0; j < m; ++j)
    for (int k = buckets[j]; k > 0; --k)
      arr[i++] = j;
}


//Driver function to test above function
int main()
{   
  int input_ar[] = {10, 24, 22, 62, 1, 50, 100, 75, 2, 3};
  int n = sizeof (input_ar) / sizeof (input_ar[0]);
  bucket_sort (input_ar, n);

  cout << "Sorted Array : " << endl;   
  for (int i = 0; i < n; ++i)
    cout << input_ar[i] << " ";   

    return 0;
}