0751~0800

/**
 * @param r: a Integer represent radius
 * @return: the circle's circumference nums[0] and area nums[1]
 */
func Calculate(r int) []float64 {
    // write your code here
    slice := make([]float64,2)
    Pi := 3.14
    slice[0] = 2 * Pi * float64(r)
    slice[1] = Pi * float64(r * r)
    return slice
}

/**
 * @param n: a number represent year
 * @return: whether year n is a leap year.
 */
func IsLeapYear(n int) bool {
    // write your code here
    if n % 4 == 0 && n % 100 != 0 || n % 400 == 0 {
        return true
    }
    return false
}

/**
 * @param nums: a integer array
 * @return: nothing
 */
func ReverseArray(nums []int)  {
    // write your code here
    l, r := 0, len(nums)-1
    for i := 0; i < len(nums)/2; i++ {
        nums[l], nums[r] = nums[r], nums[l]
        l++
        r--
    }
}