[LeetCode By Go 74]83. Remove Duplicates from Sorted List

本题目测试中给出了 初始化链表 和 判断两个链表是否相同 的方法

题目

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

解题思路

遍历链表，去掉重复的元素
注意
go语言不需要回收内存

代码

removeDuplicates.go

package _83_Remove_Duplicates_from_Sorted_List

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */

type ListNode struct {
    Val int
    Next *ListNode
}

func DeleteDuplicates(head *ListNode) *ListNode {
    if nil == head {
        return nil
    }

    newHead := head
    p := head
    q := head.Next
    for ; q != nil ; {
        if p.Val == q.Val {
            p.Next = q.Next
            q.Next = nil
            q = p.Next
        } else {
            p = q
            q = q.Next
        }
    }

    return newHead
}

测试

removeDuplicates_test.go

package _83_Remove_Duplicates_from_Sorted_List

import "testing"

func InitList(nums []int) (head *ListNode)  {
    len1 := len(nums)
    if len1 == 0 {
        return nil
    }

    head = new(ListNode)
    head.Val = nums[0]
    head.Next = nil

    p := head
    for i := 1; i < len1; i++ {
        q := new(ListNode)
        q.Val = nums[i]
        q.Next = nil

        p.Next = q
        p = q
    }

    return head
}

func ListEqual(list1, list2 *ListNode) bool {
    if nil == list1 && nil == list2 {
        return true
    } else if nil != list1 && nil == list2 {
        return false
    } else if nil == list1 && nil != list2 {
        return false
    }

    for ; nil != list1 && nil != list2; {
        if list1.Val != list2.Val {
            return false
        }
        list1 = list1.Next
        list2 = list2.Next
    }

    if nil == list1 && nil == list2 {
        return true
    }

    return false
}

func TestDeleteDuplicates(t *testing.T) {
    input1 := []int{1, 1, 2, 3, 3}
    inputList := InitList(input1)
    output1 := []int{1, 2, 3}
    outputList := InitList(output1)
    var tests = []struct{
        input *ListNode
        output *ListNode
    } {
        {inputList, outputList},
    }

    for _, v := range tests {
        ret := DeleteDuplicates(v.input)
        ok := ListEqual(ret, v.output)
        if ok {
            t.Logf("pass")
        } else {
            t.Errorf("fail, want %+v, get %+v\n", v.output, ret)
        }
    }
}