Question

I was not sure how to utilize this line because I made code that works but not with this line specifically. C++

Function 2:
bool exists_trio_within_distance(int*,int,int);
//Input:
   //an integer array (param 1), its size (param 2), and
   //a distance (param 3)

//Output:
   //True or false

//Behavior:
   //Returns true is there exists
   //a sequence of 3 values in the array
   //such that sum of the first two elements
   //is equal to the third element in the
   //sequence. The third element has to be
   //within a distance of dist from the
   //second element.
   //False otherwise.

//Example:
   //For the array {3,4,1,3,17,3,96,21,5,20},
   //if dist is 7
   //the function returns true because
   // 4+1=5 and the element 5 is within 7 spots
   //from element 1.

   //For the array {3,4,1,3,3,7},
   //if dist is 2,
   //the function returns false.
   //This is because, even though, for example, 3+4=7,
   //element 7 is not within a distance of 2
   //from element 4.

int main()
{
   const int asize=10;
   int a[asize]={3,4,1,3,17,3,20,21,5,20};

   const int bsize=6;
   int b[bsize]={3,4,1,3,3,7};
   //////////////////////////////////////////

   //test exists_trio function

   //should print "A trio exists."
   if (exists_trio(a,asize))
       cout << "A trio exists.\n";
   else
       cout << "A trio does not exist.\n";

   //should print "A trio does not exist."
   if (exists_trio(b,bsize))
       cout << "A trio exists.\n";
   else
       cout << "A trio does not exist.\n";

   cout << "=========================\n";

   //////////////////////////////////////////////

   //test exists_trio_within_distance function

   //if you only want to test exists_trio, comment
   //out the below code

   //change the array a to help test Function 2
   a[6]=209; //change a[6] from 20 to 209
   int dist=7;
   //should print "A trio exists within distance 7."
   if (exists_trio_within_distance(a,asize,dist))
       cout << "A trio exists within distance " << dist << "." << endl;
   else
       cout << "A trio does not exist within distance " << dist << "." << endl;

   dist=2;
   //should print "A trio does not exist within distance 2."
   if (exists_trio_within_distance(b,bsize,dist))
       cout << "A trio exists within distance " << dist << "." << endl;
   else
       cout << "A trio does not exist within distance " << dist << "." << endl;
}

Answer 1

#include<bits/stdc++.h>
using namespace std;

bool exists_trio_within_distance(int* arr, int n , int d) {

  for (int i = 0; i < n - 2; ++i) {

    int sum = arr[i] + arr[i + 1];
    int j = i + 2;

    for (int k = 0; k < d ; ++k) {

      if (arr[k + j] == sum) {
        return true;
      }

    }

  }
  return false;
}
//Input:
//an integer array (param 1), its size (param 2), and
//a distance (param 3)

//Output:
//True or false

//Behavior:
//Returns true is there exists
//a sequence of 3 values in the array
//such that sum of the first two elements
//is equal to the third element in the
//sequence. The third element has to be
//within a distance of dist from the
//second element.
//False otherwise.

//Example:
//For the array {3,4,1,3,17,3,96,21,5,20},
//if dist is 7
//the function returns true because
// 4+1=5 and the element 5 is within 7 spots
//from element 1.

//For the array {3,4,1,3,3,7},
//if dist is 2,
//the function returns false.
//This is because, even though, for example, 3+4=7,
//element 7 is not within a distance of 2
//from element 4.

int main()
{
  const int asize = 10;
  int a[asize] = {3, 4, 1, 3, 17, 3, 20, 21, 5, 20};

  const int bsize = 6;
  int b[bsize] = {3, 4, 1, 3, 3, 7};
  //////////////////////////////////////////

  //test exists_trio function

  //should print "A trio exists."
  // if (exists_trio(a, asize))
  //   cout << "A trio exists.\n";
  // else
  //   cout << "A trio does not exist.\n";

  //should print "A trio does not exist."
  // if (exists_trio(b, bsize))
  //   cout << "A trio exists.\n";
  // else
  //   cout << "A trio does not exist.\n";

  // cout << "=========================\n";

  //////////////////////////////////////////////

  //test exists_trio_within_distance function

  //if you only want to test exists_trio, comment
  //out the below code

  //change the array a to help test Function 2
  a[6] = 209; //change a[6] from 20 to 209
  int dist = 7;
  //should print "A trio exists within distance 7."
  if (exists_trio_within_distance(a, asize, dist))
    cout << "A trio exists within distance " << dist << "." << endl;
  else
    cout << "A trio does not exist within distance " << dist << "." << endl;

  dist = 2;
  //should print "A trio does not exist within distance 2."
  if (exists_trio_within_distance(b, bsize, dist))
    cout << "A trio exists within distance " << dist << "." << endl;
  else
    cout << "A trio does not exist within distance " << dist << "." << endl;
}

OUTPUT: