Difficult:Medium
題目
Given the head of a linked list, rotate the list to the right by k places.
翻譯
給定鍊錶的頭部，將鍊錶向右旋轉 k 位。
範例
Example 1
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| Input: head = [1,2,3,4,5], k = 2
Output: [4,5,1,2,3]
|
Example 2
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| Input: head = [0,1,2], k = 4
Output: [2,0,1]
|
解題思路
1.先算出node長度
2.反轉node將最後的依序往前
Solution
Code 1 :
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| var rotateRight = function (head, k) {
if (head == null || head.next == null || k == 0) {
return head;
}
let headnode = head;
let curnode = headnode;
let prenode;
let length = 1;
while (curnode.next != null) {
prenode = curnode;
curnode = curnode.next;
length++;
}
prenode.next = null;
curnode.next = headnode;
headnode = curnode;
k = (k - 1) % length;
for (let i = 0; i < k; i++) {
while (curnode.next != null) {
prenode = curnode;
curnode = curnode.next;
}
prenode.next = null;
curnode.next = headnode;
headnode = curnode;
}
return curnode;
};
|