https://github.com/charles-wangkai/hackerrank/tree/master/and-xor-or

you can also use the swap case built-in function
most people don't know that its exist

def swap_case(s):
    return s.swapcase()

if __name__ == '__main__':
    s = input()
    result = swap_case(s)
    print(result)

happy coding

It can be like this:

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Solution {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);

	Map<String, String> name2phone = new HashMap<String, String>();

	int n = sc.nextInt();
	sc.nextLine();

	for (int i = 0; i < n; i++) {
		String name = sc.nextLine();
		String phone = sc.nextLine();

		name2phone.put(name, phone);
	}

	while (sc.hasNext()) {
		String name = sc.nextLine();

		if (name2phone.containsKey(name)) {
			System.out.println(name + "=" + name2phone.get(name));
		} else {
			System.out.println("Not found");
		}
	}

	sc.close();
}

}

Just need to do a little change. Thanks.

In line 21 and line 22 in the main code of even tree,write u1-1 and vi-1 instead of ui and vi,since they are giving out of bounds exception.
adjacentLists[ui-1].add(vi-1); adjacentLists[vi-1].add(ui-1);

Hi @charles-wangkai, I hope you're doing well

If you have 10min, would you add a few comments for this solution?
https://github.com/charles-wangkai/hackerrank/blob/c418fb24e08e5c57a1bd0d91f95ab2af32f01c64/decibinary-numbers/Solution.java

I want to understand deeper buildF method and why do you use left-shift and why variable names are C, F, S?

PS:
(If you don't have time, just close this issue)
Sorry for this question and thank you!

`#!/bin/python3

import sys
import math

def encryption(s):
L = len(s)
r = math.floor(math.sqrt(L)) #2
c = math.ceil(math.sqrt(L)) #3
arr = []
n=0
for i in range(r):
a = []
for j in range(c):
if n < L:
a.append(s[n])
else:
break
n+=1
arr.append(a)
print(arr)
resStr = ''
for i in range(c):
for j in range(r):
try:
resStr += arr[j][i]
except IndexError:
break
resStr += ' '
return resStr

if name == "main":
s = input().strip()
result = encryption(s)
print(result)
`

Hello,
Did your "Truck Tour" problem solution passed all test cases? It seems may fail in many cases. If last petrol pump loads still causes fuel negative then where it should point?

public static boolean isFibo(int valueToCheck, int previousValue, int currentValue) {
return currentValue > valueToCheck ? false : valueToCheck == currentValue ? true : isFibo(valueToCheck, currentValue, currentValue + previousValue);
}

Can you please provide explanation of truck tour problem in hackerrank....And it helped me to clear assessment...Thanks

File is invalid : wrong while submitting code.