C++ :: Finding Second Smallest Element In Unsorted Array

How should I go about finding the 2nd, or 3rd smallest element in an array? Where the minimum is not equals to the next minimum.

Here is the psuedocode I've found

void Min(A[i..j], int&min, int &next_min)
if (i=j) then min=A[i] and next_min = infinity
else
mid = (i+j)/2
Min(A[i to mid]),a,b)
Min(A[mid+1 to j],c,d)

Let min be minimum among a,b,c,d

Let next_min be the next_min among a,b,c,d

min != next_min

Here is what I wrote but it does not seem to work.

#include<iostream>
#include<vector>
#include <cstdlib>
using namespace std;
void minfind(vector<int> &array,int left,int right, int &min, int &next_min);

[Code]...