refer to ： https://www.algoexpert.io/questions/Subarray%20Sort

Problem Statement

 

 Analysis

 

 

Code

def subarraySort(array):
    minOutOfOrder = float("inf")
    maxOutOfOrder = float("-inf")
    for i in range(len(array)):
        num = array[i]
        if isOutOfOrder(i, num, array):
            minOutOfOrder = min(minOutOfOrder, num)
            maxOutOfOrder = max(maxOutOfOrder, num)
    if maxOutOfOrder == float("-inf"):# or if minOutOfOrder == float("inf"), which means line 6 never has been hit, no unsorted values
        return [-1,-1]
    #check the correct position for the smallest valur of all the out of order values, from left to right
    subarrayLeftIdx = 0
    while minOutOfOrder >= array[subarrayLeftIdx]:
        subarrayLeftIdx += 1
    #check the correct position for the greatest valur of all the out of order values, from right to left
    subarrayRightIdx = len(array) - 1
    while maxOutOfOrder <= array[subarrayRightIdx]:
        subarrayRightIdx -= 1
    return [subarrayLeftIdx, subarrayRightIdx]
        
# compare the current value to its two adjcent values
# the first value has no left value, the last one has no right value
def isOutOfOrder(i, num, array):
    if i == 0:
        return num > array[i + 1]
    if i == len(array) - 1:
        return num < array[i - 1]
    return num > array[i + 1] or num < array[i - 1]