This is a C++ program to find Second Smallest of n elements with given complexity constraint.
Algorithm
Begin
function SecondSmallest() :
/* Arguments to this function are:
A pointer array a.
Number of elements n
*/
// Body of the function:
A variable s1 is declared as to keep track of smallest number.
A variable s2 is declared as to keep track of second smallest number.
Initialize both s1 and s2 with INT_MAX.
Traverse the data array using iteration.
If current array element is lesser than current value in s1, then s2 = s1 and s1 =
current array element.
Else if array element is in between s1 and s2,
then s2 = current array element.
if(s2==INT_MAX)
Print “no second smallest element is present".
else
Print s2 as second smallest element.
End
Example
#include<iostream>
#include <climits> //for INT_MAX
using namespace std;
int SecondSmallest(int *a, int n) {
int s1, s2, i,t;
//initialize s1 and s2
s1 =INT_MAX;
s2=INT_MAX;
for(i = 0; i < n; i++) {
//If current element is smaller than s1
if(s1 > a[i]) {
//update s1 and s2
s2 = s1;
s1 = a[i];
}
//if a[i] is in between s1 and s2
else if(s2 > a[i] && a[i]!=s1) {
//update only s2
s2 = a[i];
}
}
if(s2==INT_MAX)
cout<<"no second smallest element is present";
else
cout<<"Second smallest element is:"<<s2;
}
int main() {
int n, i;
cout<<"Enter the number of elements: ";
cin>>n;
int array[n];
for(i = 0; i < n; i++) {
cout<<"Enter "<<i+1<< " "<<"element: ";
cin>>array[i];
}
SecondSmallest(array, n); //call the function
return 0;
}
Output
Enter the number of elements: 5
Enter 1 element: 1
Enter 2 element: 2
Enter 3 element: 1
Enter 4 element: 3
Enter 5 element: 4
Second smallest element is:2