使用插入排序查找重复项答案

【问题标题】：Find duplicate using insertion sort使用插入排序查找重复项
【发布时间】：2021-01-30 11:43:23
【问题描述】：

def find_duplicate(arr):
    for i in range(1, len(arr)):
        cur = arr[i]
        j = i
        while j > 0 and arr[j - 1] > cur:
            arr[j] = arr[j - 1]
            j -= 1
        arr[j] = cur
        if arr[j-1] == cur:
            arr[j] = cur
            return f"This is the duplicate {cur}, {arr}"
        else:
            arr[j] = cur
    print("no dupes")
    return arr


print(find_duplicate([1,-5,3,4,-10,100,250,-325,100]))

当我在数组末尾添加 100 时，它会被排序，并且重复值显示为 100 并且数组已正确排序，但是当我在末尾添加一个负数说 -5 作为重复项时，它不对 -5 进行排序，但有些人如何理解这个数字是重复的。我做错了什么？

请查看我提到的两个数组作为输入：

arr = [1,-5,3,4,-10,100,250,-325,100] arr = [1,-5,3,4,-10,100,250,-325,-5]

print(find_duplicate([1,-5,3,4,-10,100,250,-325,100]))

print(find_duplicate([1,-5,3,4,-10,100,250,-325,-5]))


# OUTPUT BELOW:


This is the duplicate 100, [-325, -10, -5, 1, 3, 4, 100, 100, 250]
This is the duplicate -5, [-5, 1, 3, 4, -10, 100, 250, -325, -5]

更新：

再次运行时

print(find_duplicate([1,-5,3,4,-10,100,250,-325,-5,10]))

this is the duplicate -5, [-325, -10, -5, -5, 1, 3, 4, 100, 250, 10]

似乎它只是在找到重复项后一直附加数字而不是对它们进行排序

【问题讨论】：

标签： python arrays algorithm sorting duplicates

【解决方案1】：

你的逻辑是对的，除了if中的return语句

def find_duplicate(arr):
    dup = None  # set this to none to act as flag
    for i in range(1, len(arr)):
        cur = arr[i]
        j = i
        while j > 0 and arr[j - 1] > cur:
            arr[j] = arr[j - 1]
            j -= 1
        arr[j] = cur
        if arr[j-1] == cur:
            arr[j] = cur
            dup = cur
        else:
            arr[j] = cur
    if dup is None:  # check if a duplicate was found
        print("no dupes")
        return arr
    else:
        return f"This is the duplicate {dup}, {arr}"


print(find_duplicate([1,-5,3,4,-10,100,250,-325,-5]))

print(find_duplicate([1,-5,3,4,-10,100,250,-325,100]))

print(find_duplicate([1,-5,3,4,-10,100,250,-325,-5,10]))

输出

This is the duplicate -5, [-325, -10, -5, -5, 1, 3, 4, 100, 250]
This is the duplicate 100, [-325, -10, -5, 1, 3, 4, 100, 100, 250]
This is the duplicate -5, [-325, -10, -5, -5, 1, 3, 4, 10, 100, 250]

【讨论】：