Program 4TH in C++

PROGRAM:

Given an array find 3 elements such that a[i] < a[j] < a[k] and i < j < k in 0(n) time.

NOTE :

It finds every possible such combination.

SOLTUION:

#include "iostream.h"

#include "cstdio"

#include "cstdlib"

#include "unistd.h"

#include "vector.h"

using namespace std;

void print(vector<int> a1, int i, int j, int k)

{

cout<<"\n\nThe element starts at position : "<i;

cout<<"\nThe elements are : "<a1[i]

<" "

<a1[j]

<" "

<a1[k];

}

int main()

{

vector<int> a;

int i=0;

int flag=1;

int j=0;

int first=0;

int mid=0;

int last=0;

int k=0;

int num=0;

//loop for entering values.

cout<<"\n\nEnter numbers : \n";

cout

<<"(Enter value other than integer to stop entering value)\n\n";

while(true)

{

cout

<endl

<endl;

cin>>num;

if(cin.good())

{

a.push_back(num);

continue;

}

else

{

cin.clear();

cin.ignore(numeric_limits<streamsize>::max(),'\n');

cout<<"\n\n You enetered non itegral value....Evaluating Array \n\n";

break;

}

}

int size = a.size();

cout<

if(size < 3)

{

cout<<"\n\nArray has less than 3 elements\n\n";

exit(0);

}

//loop to find elements

while(i < size )

{

first = a[j];

if(i != j)

{

//setting mid value only if none of the secod is found.

if(a[i] > first && k==0)

{

mid = a[i];

k=i;

}

else if(a[i] > mid && k!=0)

{

last = a[i];

flag=0;

print(a,j,k,i);

if( k < size-2)

{

i=++k;

k=0;

}

else

{

i=++j;

k=0;

}

continue;

}

//checking for finding mid element to further position of k, if at that case 3rd element was not found.

if( i == size-1 && j < size-3)

{

if(k < size-2 && k!=0)

{

i=++k;

k=0;

continue;

}

else

{

//changing the first value only if no second value is availaible wrt a[j].

i=++j;

k=0;

continue;

}

}

}

i++;

}

if(flag != 0)

{

cout<<"\n\n Such elements dont exist in the array \n\n";

}

}