如何在Groovy中删除{(字符串中模式的第n次出现)或(连接字符串的第n部分)}？

def removeNthOccurrence(String input, String pattern, int n) {
    def count = 0
    input.replaceAll(pattern) {
        if (++count == n) {
            ''
        } else {
            it
        }
    }
}

def input = "Hello World Hello World Hello World"
def pattern = "World"
def n = 2

def result = removeNthOccurrence(input, pattern, n)
println result

def concatenateNthPart(String[] parts, int n) {
    def result = ''
    for (int i = 0; i < parts.length; i++) {
        if (i == n - 1) {
            result += parts[i]
        }
    }
    result
}

def parts = ["Hello", "World", "Groovy", "Programming"]
def n = 3

def result = concatenateNthPart(parts, n)
println result