codingbat.java

//The parameter weekday is true if it is a weekday, and the parameter vacation is true if we are on vacation. We sleep in if it is not a weekday or we're on vacation. Return true if we sleep in.

public boolean sleepIn(boolean weekday, boolean vacation) {
return  !weekday||vacation ? true: false;
}


//Given an int n, return the absolute difference between n and 21, except return double the absolute difference if n is over 21.

public int diff21(int n) {
  return n > 21 ? Math.abs(21-n)*2 :21-n;
}



//Given an int n, return true if it is within 10 of 100 or 200. Note: Math.abs(num) computes the absolute value of a number.

public boolean nearHundred(int n) {
	int targetTolerance=10;
	int[] targetNumbers= new int[2];
	targetNumbers[0]=100;
	targetNumbers[1]=200;
	
	for (int o : targetNumbers){
		if (Math.abs(o-n)<=targetTolerance) {
			return true;
		}
	}
	return false;
}



//Given a non-empty string and an int n, return a new string where the char at index n has been removed. The value of n will be a valid index of a char in the original string (i.e. n will be in the range 0..str.length()-1 inclusive).

public String missingChar(String str, int n) {
	StringBuilder StringLessCharAtIndex= new StringBuilder();
	for(int i=0; i<str.length(); i++){
		if(i!=n){
			StringLessCharAtIndex.append(str.charAt(i))  ;
		}
	}
	
	return StringLessCharAtIndex.toString();
}

public String missingChar(String str, int n) {
  String front = str.substring(0, n);
  
  String back = str.substring(n+1, str.length());
  
  return front + back;
}

//Given a string, take the last char and return a new string with the last char added at the front and back, so "cat" yields "tcatt". The original string will be length 1 or more.