Write a function | HackerRank

Goal

This task is to return true if a give year is a leap year, otherwise return false

Solution

There are three main conditions to check leap year:

1. It can be evenly divided by 4 - leap year

2. It can be evenly divided by 100, it is NOT a leap year, unless it is evenly disivible by 400 - leap year

3. Otherwise it is not a leap year.

These conditions can be shown in this code.

# Write a function

def is_leap(year):
    leap = False
    
    # Write your logic here
    if year % 4 == 0:
        if year % 100 == 0:
            if year % 400 == 0:
                leap = True
            else : 
                leap = False
        else:  
            leap = True
        
    else:
        leap = False
    
    return leap

year = int(input())
print(is_leap(year))

For Loop | HackerRank

Goal

Print results according to two positive input values by using for loop statement.

Solution

To solve easily, I create vector string array included 1-9 numbers. If you use vector array, you can print numbers easily.

// For Loop
#include <iostream>
#include <cstdio>
#include <vector>
#include <string>
using namespace std;

int main() {
    // Complete the code.
    int a,b;
    cin >> a;
    cin >> b;
    
    vector<string> numbers {"", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};
    
    for(int i = a; i <= b; i++){
        
        if(i>9){
            if( i % 2 == 0){
                cout << "even" << endl;
            }
            else{
                cout << "odd" << endl;
            }
        }
        
        else{
            
            cout << numbers[i] << endl;
        }
    }
    
    return 0;
}

https://www.hackerrank.com/challenges/c-tutorial-conditional-if-else/problem

Goal

Solution

You just need to create condtion statements for each condition like below.

// Conditional Statements

#include <bits/stdc++.h>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);



int main()
{
    string n_temp;
    getline(cin, n_temp);

    int n = stoi(ltrim(rtrim(n_temp)));

    // Write your code here
    if(n > 9){
        printf("Greater than 9");
    }
    else if(n == 1){
        printf("one");
    }
    else if(n == 2){
        printf("two");
    }
    else if(n == 3){
        printf("three");
    }
    else if(n == 4){
        printf("four");
    }
    else if(n == 5){
        printf("five");
    }
    else if(n == 6){
        printf("six");
    }
    else if(n == 7){
        printf("seven");
    }
    else if(n == 8){
        printf("eight");
    }
    else { // n == 9
        printf("nine");
    }

    return 0;
}

string ltrim(const string &str) {
    string s(str);

    s.erase(
        s.begin(),
        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
    );

    return s;
}

string rtrim(const string &str) {
    string s(str);

    s.erase(
        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
        s.end()
    );

    return s;
}