Session 3: Basics of Programming

Agenda - Revision of basic concepts in C++, Java and Python

Duration - 3 hours

Conditional Statements - If, If-Else, If-Else-If ladder, Nested If-Else, Switch Case

Loops - For, While, Do-While, For-Each

Arrays - 1D and 2D

1. WAP to accept a score from a student. Print a congratulatory message if the score of student is greater than 75

// Online C++ compiler to run C++ program online
#include <bits/stdc++.h>

using namespace std;


int main() {
    int score;
    cout << "Enter your score: ";
    cin >> score; // score = 79
    /*
        if(<condition>){
            line 1
            line 2
        }
    */
    
    if(score>75){
        cout << "Congratulations!!" << endl;
        cout << "Well done!" << endl;
    }
    
    return 0;
}

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        System.out.print("Enter your score: ");
        Scanner sc = new Scanner(System.in);
        int score = sc.nextInt(); // scoer = 78
        
        if(score>75){
            System.out.println("Congratulations!!");
            System.out.println("Partyyyyy!!");
        }
    }
}

score = int(input("Enter your score: "))
if(score>75):
    print("Congratulations!")
    print("Partyyyy")

2. WAP to accept a score from a student. Print a congratulatory message if the score of student is greater than 75. If the score is ≤ 75, print some relevant message.

// Online C++ compiler to run C++ program online
#include <bits/stdc++.h>

using namespace std;


int main() {
    int score;
    cout << "Enter your score: ";
    cin >> score; // score = 79
    
    if(score>75){
        cout << "Congratulations!!" << endl;
        cout << "Well done!" << endl;
    }
    else{
        cout << "Better luck next time" << endl;
    }
    
    return 0;
}

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        System.out.print("Enter your score: ");
        Scanner sc = new Scanner(System.in);
        int score = sc.nextInt(); // score = 78
        
        if(score>75){
            System.out.println("Congratulations!!");
            System.out.println("Partyyyyy!!");
        }
        else{
            System.out.println("Better luck next time");
            System.out.println("Cheer up!");
        }
    }
}

score = int(input("Enter your score: "))
if(score>75):
    print("Congratulations!")
    print("Partyyyy")
else:
    print("Sorry, you've failed")
    print("You can try again next year.")

If BBD sale = Buy from Flipkart

Else if TGIF sale = Buy from Amazon

Else if ABCD sale = Buy from ABCD

Else = Buy from store

3. WAP to accept an integer from a user and print the corresponding message based on the following conditions
   1. Divisible by both 5 and 8 ⇒ Print 58
   2. Divisible only by 5 ⇒ Print 5
   3. Divisible only by 8 ⇒ Print 8
   4. Divisible by neither 5 nor 8 ⇒ Print “None”

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        System.out.print("Enter your number: ");
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt(); // score = 78
        
        if(num%5==0 && num%8==0)
            System.out.println(58);
        else if(num%5==0)
            System.out.println(5);
        else if(num%8==0)
            System.out.println(8);
        else
            System.out.println("None");
    }
}

4. WAP to print Gold Medal if score of student is 100.

// Online C++ compiler to run C++ program online
#include <bits/stdc++.h>

using namespace std;


int main() {
    int score;
    cout << "Enter your score: ";
    cin >> score; // score = 79
    
    if(score==100)
        cout << "Gold Medal" << endl;
    
    return 0;
}

= → Assignment operator

== → Comparison operator

5. WAP to find largest of 3 distinct numbers using Nested If-Else

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        
        int a = 300, b = 50, c = 70;
    
        if(a>b){
            // b is out of race
            if(a>c)
               System.out.println("A is the greatest");
            else
                System.out.println("C is the greatest");
        }
        else{
            // b>a
            // a is out of race
            if(b>c)
                System.out.println("B is the greatest");
            else
                System.out.println("C is the greatest");
        }
    }
}

6. WAP to print multiplication table of a number

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter your number: ");
        int num = sc.nextInt();
        for(int i=1;i<=10;i++)
            System.out.println(num + " * " + i + " = " + (num*i));
    }
}

7. WAP to print multiplication table of a number. Skip the 5th multiple always.

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter your number: ");
        int num = sc.nextInt();
        for(int i=1;i<=10;i++){
            if(i==5)
                continue;
            System.out.println(num + " * " + i + " = " + (num*i));
        }
    }
}

8. WAP to print multiplication table of a number. If any multiple comes up as 42, exit out of loop.

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter your number: ");
        int num = sc.nextInt();
        for(int i=1;i<=10;i++){
            if(num*i==42)
                break;
            System.out.println(num + " * " + i + " = " + (num*i));
        }
    }
}

7. WAP to keep taking integral input from user till they enter 42

// Online Java Compiler
// Use this editor to write, compile and run your Java code online

import java.util.*;

class HelloWorld {
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(true){
            System.out.print("Enter your number: ");
            int num;
            num = sc.nextInt();
            if(num==42)
                break;
        }
    }
}

9. WAP to find sum of first N odd natural numbers.

Examples -

N = 5

1+3+5+7+9 = 25

N = 4

1+3+5+7= 16

public class codefile{
    static int solve(int n){
		int sm = 0;
            for(int i=1;i<2*n;i+=2)
                  sm += i;
            return sm;
    }
}

10. Primality Check: Given a number, check if it is prime or not.

A number is prime if it is divisible only by 1 and itself.

public class codefile{
    static boolean check(int n){
		for(int i=2;i*i<=n;i++){
            if(n%i==0)
                return false;
        }
        return true;
    }
}

11. Concatenate the array: Given an Array of size N. Create another array of size 2*N and place the array first and then its copy in the new array.

    A = [2,4,3]

    ans = [2,4,3,2,4,3]

    A = [6,4,1,7]

    ans = [6,4,1,7,6,4,1,7]

public class codefile{
    static int[] solve(int[]  input){
        int n = input.length;
        int []ans = new int[2*n];
        for(int i=0;i<n;i++){
            ans[i] = input[i];
            ans[i+n] = input[i];
        }
        return ans;
    }
}

12. Given an array, create running sum array from it.

arr = [2,4,3,1,0,9]

rSum =[2,6,9,10,10,19]

public class codefile{
    static int[] sum(int[]  input){
        int n = input.length;
         int sm = 0;
        int []ans = new int[n];
        for(int i=0;i<n;i++){
            sm += input[i];
            ans[i] = sm;
        }
        return ans;
    }
}

TC: O(N)

Sum of diagonals

Time Complexity: N

public class codefile{
    static int solve(List<List<Integer>>  input){
        int sm = 0;
        int n = input.size();
        for(int i=0;i<n;i++){
            sm+=input.get(i).get(i);
            if(i!=n-i-1)
                sm+=input.get(i).get(n-i-1);
        }
        return sm;
    }
}

Richest Customer Wealth

public class codefile{
    static int solve(List<List<Integer>>  input){
        int ans = 0;
        int n = input.size();
        int m = input.get(0).size();
        for(int i=0;i<n;i++){
            int sm = 0;
            for(int j=0;j<m;j++)
                sm += input.get(i).get(j);
            if(sm>ans)
                ans = sm;
        }
        return ans;
    }
}