题解 | #链表中环的入口结点#

先用一个map存起来，然后一旦发现有相同的node与map中的相同就知道这个就是入口； import java.util.; / public class ListNode { int val; ListNode next = null;

ListNode(int val) {
    this.val = val;
}

} */ public class Solution {

public ListNode EntryNodeOfLoop(ListNode pHead) {
    HashMap testMain = new HashMap();
    while(pHead != null){
        if(pHead.next == pHead){
            return pHead;
        }
        if(pHead.next == null)
            return null;
        if(pHead.next == testMain.get(pHead.hashCode())){
            return pHead;
        }
        testMain.put(pHead.hashCode(),pHead.next);
        pHead = pHead.next;
    }
    return null;
}

}

#include <iostream>

int main() {
    std::cout << "Hello World!";
    return 0;
}

class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!"); 
    }
}

print('Hello world!')