Question

Task is:

• There are 2 arrays A (numeric floating type) and B is a character array. A is populated with random numbers.
• Let A[i] denote the ith value which is associated with the ith character from B array.That is, every unique Ai is mapped /associated with a unique Bi. So,if there are similar Ai’s then each one of them would be associated with the same character from B sequentially.
• Now, there is a new array which New_A which is populated by random numbers which may be slightly different from that of A or few numbers may be exactly the same. The task is to create a character array New_B based on the following assumption :
• We find the smallest Euclidean distance or any measure between New_A[j] and A[i] such that given a New_A[j], the character from B is assigned where A[i] >=New_A[j] (New_A[i] >= A[j]). Let small_A denote the index j of the smallest A[j] for which the condition holds.
• For ex, say the character associated with A[2] is ‘d’ and value at A[2]=12.1 and value at New_A[7]=11.9. Because, A[2]> New_A[7],New_A[7] gets mapped/associated with the character which was initially associated with A[2] which is character ‘d’ ; the rest where this condition does not hold remain unchanged. Therefore,the overall effect/objective is to create a variation of the character array B into a new character array New_B according to New_A and A.

Now,this is where I am stuck. How to find the smallest Euclidean value and then how to assign the characters of B following the condition. Moreover,the data types of the arrays are different so how would the association be done. Usage of 2D arrays was a pure guess work and there is no guarantee that I am correct.

float A[10];
char B[10] = {'c','d','e','f','g','h','i','j','k','l'} ; 

for (i = 1; i <= 10; i++) {
  Val_A[i] = rand(); 
  Val_New[i] = rand();
  A[i] = Val_A[i]; 
  New_A[i][j] = Val_New[i]; 
}

max1 = New_A[0];
index1 = 0; 
for (i = 1; i < 10; i++) {
  if (A[i] > max1)
    extract_char = B[i];  
  New_A[i][j] = extract_char;  
  //assigning corresponding character to New_A, which was assigned earlier to A   
  index1 = i;
}

Answer 1

First of all euclidean distance for scalars is just a fancy way of saying “absolute value of the difference” e.g. fabs(a-b)

For each element “i” in New_A:

1. ind the element indexed “minA” in A with the smallest euclidean distance
2. Set New_B[i] to B[minA]

First step 1:

int findminA(float A[], int sizeA, float compare)
{
  int i;
  int minA=0;
  float best=abs(a[0]-compare);
  for(i=1;i<sizeA;++i) {
    if(fabs(A[i]-compare)<best) {
       best=fabs(A[i]-compare)
       minA=i;
  }
  return i;
}

This gets you the index (for A and B) that has the smallest euclidean distance.