// function for finding Kth smallest element
int kthSmallest(int arr[], int l, int r, int k)
{
if (k > 0 && k <= r - l + 1)
{
int pos = randPart(arr, l, r); // position of random partition
// now compairing pos with Kth position
if (pos == k - 1)
return arr[pos];
else if (pos > k - 1)
return kthSmallest(arr, l, pos - 1, k);
return kthSmallest(arr, pos + 1, r, k);
}
return INT_MAX;
}
It gives random output:
PS C:\Users\anmol\Desktop\c++projectwork> g++ .\450\3.-KthMinOrMaxEle.cpp
PS C:\Users\anmol\Desktop\c++projectwork> ./a
enter n and k:
6 3
enter array elements:
7 10 4 3 20 15
answer element:2147483647
The above is my code but solution code has some difference. Solution code is as:
int kthSmallest(int arr[], int l, int r, int k){
if (k > 0 && k <= r - l + 1){
int pos = randPart(arr, l, r); // position of random partition
if (pos - l == k - 1){ // pos-l not pos why?
return arr[pos];
}
else if (pos - l > k - 1)
return kthSmallest(arr, l, pos - 1, k);
return kthSmallest(arr, pos + 1, r, k - pos + l - 1);
}
return INT_MAX;
}
Why my code is not working because i think randomPartition function(randPart()) return pos index according to orignal array indexing and k-1 is also according to orignal array indexing, So why there is need to convert them?
