Question

Please use C++

1. A Sequence of numbers and a sum is given as input. List all combinations of numbers that can add upto the given Sum.

User input:-

Enter numbers: -   1, 3,7,9,11

Enter a sum :- 20

Output:

11+9 = 20

1+3+7+9 = 20

2. Print absolute prime numbers between a given range:-

Enter Range - 2,99

For eg Prime numbers are:-

Prime numbers ==> 2,3,5,7,11,13,17,19,23

Absolute Prime numbers ==> 2,3,5,7,11,23

3. Write an encoder and decoder program, which should give us options to encode/decode?

  

   Do you want to encode or decode? [e,d]

   >>e

   Enter string to encode :- "Hello How are you?"

   Encoded string: "SDFAF@sfdfrtre"

   Do you want to encode or decode? [e,d]

   >>d

   Enter string to decode:- "SDFAF@sfdfrtre"

   Decoded string: "Hello How are you?"

Answer 1

1. #include<bits/stdc++.h>

using namespace std;

void unique (int l, int s, int k, vector<int>& local, vector<int>& a)

{

if (s==k)

{

cout<<"{";

for(int i=0; i< local.size();i++){

if(i!=0)

cout<<", ";

cout<<local[i];

if(i!= local.size()-1)

cout<<" , ";

}

cout<<" }"<<endl;

return;

}

for(int i=1; i < a.size(); i++){

if(s +a[i] > k)

continue;

if(i and a[i] == a[i -1] and i >l)

continue;

local.push_back(a[i]);

unique(i+1, sum + a[i], k, local, a);

local.pop_back();

}

}

void com(vector<int> a, int k)

{

sort(a.begin(), a.end());

vector<int> local;

unique(0,0,k,local,a);

}

int main()

{

vector<int> a={10,1,2,7,6,1,5};

int k= 8;

com(a,k);

return(0);

}

2) #include<upstream.h>

using namespace std;

void prime(int n)

{

int d=0;

for(int i=2; i<= n/2; i++)

{

if(n%i == 0)

d++;

}

if(d==1)

cout<<n<<endl;

}

int main()

{

cout<<" Enter range";

int l,u;

cin>>l>>u;

cout<<" Prime nos between " <<l<<" and "<<" are:"<<endl;

for(int i=l;i<= u; i++)

prime(i);

return 0;

}

3)