Embedded Files
/*1*/import java.lang.IllegalArgumentException;
public class MyClass {
public static double toMeters(double in, String units) {
switch (units) {
case "inch": return in * 0.3048 / 12.0;
case "foot": return in * 0.3048;
case "yard": return in * 0.3048 * 3.0;
case "mile": return in * 0.3048 * 5280.0;
}
throw new IllegalArgumentException("bad units string");
}
public static void main(String []args){
System.out.println(toMeters(56.8, "inch"));
System.out.println(toMeters(56.8, "foot"));
System.out.println(toMeters(56.8, "yard"));
System.out.println(toMeters(56.8, "mile"));
}
}
/*2*/public class MyClass {
public static String format(String tenDigits) {
return "("+tenDigits.substring(0,3)+") "+
tenDigits.substring(3, 6)+"-"+
tenDigits.substring(6);
}
public static void main(String []args){
System.out.println(format("9876543210"));
System.out.println(format("1234056789"));
System.out.println(format("3216789045"));
System.out.println(format("4545456767"));
}
}
/*3*/public class MyClass {
public static double height(double velocity, double angle, double gravity) {
assert(velocity >= 0 && angle >=0 && angle <= 180 && gravity > 0);
angle = Math.toRadians(angle);
return velocity*velocity*(Math.sin(angle))*(Math.sin(angle))/(gravity*2);
}
public static void main(String []args){
System.out.println(height(30, 20, 9.80665));
System.out.println(height(30, 90, 9.80665));
}
}
/*4*/public class MyClass {
public static String reverse(String in) {
String out = "";
for (int i=0; i<in.length(); i++) out = in.charAt(i) + out;
return out;
}
public static void main(String []args){
System.out.println(reverse("hello world"));
System.out.println(reverse(""));
System.out.println(reverse("how now brown cow"));
}
}
/*5*/public class MyClass {
public static boolean isInt(double d) {
int i = (int)d;
return (double)i == d;
}
public static void main(String []args){
for (String s : args) {
System.out.print(s+" "+isInt(Double.parseDouble(s)));
System.out.println();
}
}
}
/*6*/import java.lang.IllegalArgumentException;
public class MyClass {
public static String toBarCode(String in) {
if (in.length() != 5) throw new IllegalArgumentException("zip must be 5 digits");
String out = "|";
int check = 0;
for (int i=0; i<6; i++) {
char ch = in.charAt(i);
if (i != 5) check += ch - '0';
switch (ch) {
case '0': out += "||:::"; break;
case '1': out += ":::||"; break;
case '2': out += "::|:|"; break;
case '3': out += "::||:"; break;
case '4': out += ":|::|"; break;
case '5': out += ":|:|:"; break;
case '6': out += ":||::"; break;
case '7': out += "|:::|"; break;
case '8': out += "|::|:"; break;
case '9': out += "|:|::"; break;
default:
throw new IllegalArgumentException("digit not 0 to 9");
} //switch char
if (i == 4) {
check %= 10;
if (check != 0) check = 10-check;
in += ""+check;
}
} //for i
return out+"|";
}
public static void main(String []args){
System.out.println(toBarCode("01212"));
System.out.println(toBarCode("95014"));
//||:|:: :|:|: ||::: :::|| :|::| :::|||
System.out.println(toBarCode("36780"));
}
}
/*7*/public class MyClass {
public static int fibonnaci(int n) {
if (n <= 0) return 0;
if (n == 1) return 1;
return fibonnaci(n-1)+fibonnaci(n-2);
}
public static void main(String []args){
System.out.println(fibonnaci(9));
}
}
/*8*/public class MyClass {
public static int factorial(int n) {
if (n <= 0) return 1;
return factorial(n-1)*n;
}
public static void main(String []args){
System.out.println(factorial(12));
}
}
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public class MyClass {
// Returns the first character of the string str
public static char firstCharacter(String str) {
return str.charAt(0);
};
// Returns the last character of a string str
public static char lastCharacter(String str) {
return str.charAt(str.length()-1);
};
// Returns the string that results from removing the first
// and last characters from str
public static String middleCharacters(String str) {
return str.substring(1, str.length()-1);
};
public static boolean isPalindrome(String str) {
// base case #1
if (str.length() <= 1) return true;
// recursive case
if (firstCharacter(str) != lastCharacter(str)) return false;
return isPalindrome(middleCharacters(str));
};
public static void checkPalindrome(String str) {
System.out.println("Is this word a palindrome? " + str);
System.out.println(isPalindrome(str));
};
public static void main(String []args) {
System.out.println(middleCharacters("rotors"));
checkPalindrome("a");
checkPalindrome("motor");
checkPalindrome("rotor");
checkPalindrome("able was i ere i saw elba");
}
}
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public class MyClass {
public static boolean isEven(int n) {
return n % 2 == 0;
};
public static boolean isOdd(int n) {
return !isEven(n);
};
public static double power(int x, int n) {
System.out.println("Computing " + x + " raised to power " + n + ".");
// base case
if (n == 0) return 1.0;
if (n == 1) return x;
// recursive case: n is negative
if (n < 0) return 1.0/power(x, -n);
double d = power(x, n/2);
// recursive case: n is odd
if (isOdd(n)) return x*d*d;
// recursive case: n is even
return d*d;
};
public static void main(String []args){
System.out.println(power(13, 11));
}
}
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