packagetest.codingbat;
public class Array1 {
// return true if first and last element of array is 6
public boolean firstLast6(int[] nums) {
int length = nums.length;
final int number = 6;
if (nums[0] == number || nums[length-1] == number)
return true;
else
return false;
}
// return true if first and last element of array is same
public booleansameFirstLast(int[] nums) {
if (nums.length == 0)
return false;
else if (nums[0] == nums[nums.length-1])
return true;
else
return false;
}
// return an integer array with value pi (3.14)
public int[] makePi() {
int[] pi = new int[]{3,1,4};
return pi;
}
// return true if first or last elements of both arrays are same
public boolean commonEnd(int[] a, int[] b) {
if(a[0] == b[0] || a[a.length-1] == b[b.length-1])
return true;
else
return false;
}
// return sum of the elements
public int sum3(int[] nums) {
int sum = 0;
for (int i = 0; i < nums.length; i++) {
sum = sum + nums[i];
}
return sum;
}
// rotate elements to the left
public int[] rotateLeft3(int[] nums) {
int temp = 0;
temp = nums[0];
for (int i = 0; i < nums.length; i++) {
if(i==nums.length-1) break;
nums[i] = nums[++i];
--i;
}
nums[nums.length-1] = temp;
return nums;
}
// return elements in reverse order
public int[] reverse3(int[] nums) {
int temp = nums[0];
nums[0] = nums[nums.length-1];
nums[nums.length-1] = temp;
return nums;
}
// find largest between first and last element and set all elements to that value
public int[] maxEnd3(int[] nums) {
int largest = 0;
largest = (nums[0] > nums[nums.length-1]) ? nums[0] : nums[nums.length-1];
for(int i = 0; i < nums.length; i++) {
nums[i] = largest;
}
return nums;
}
// return the sum of the first 2 elements in the array.
// If the array length is less than 2, just sum up the elements that exist,
// returning 0 if the array is length 0.
public int sum2(int[] nums) {
if (nums.length == 0 ) return 0;
else if (nums.length == 1) return nums[0];
else return nums[0] + nums[1];
}
// Given 2 int arrays, a and b, each length 3,
// return a new array length 2 containing their middle elements.
public int[] middleWay(int[] a, int[] b) {
int newArray[] = new int[]{a[1],b[1]};
return newArray;
}
// Given an int array, return a new array with double the length where its last element
// is the same as the original array, and all the other elements are 0.
// The original array will be length 1 or more.
public int[] makeLast(int[] nums) {
int length = nums.length;
int newArray[] = new int[2*length];
newArray[newArray.length-1] = nums[nums.length-1];
return newArray;
}
}
