All numbers in an array of length n are in the range of 0 to n-1. Some numbers in the array are repeated, but I do not know how many numbers are repeated. I don't know how many times each number repeats. Please find any duplicate number in the array. For example, if the input array of length 7 is {2,3,1,0,2,5,3}, then the corresponding output is the first repeated number 2.
class solution:
def duplicate(self,list,duplication):
for x in range(len(list)):
while list[x] != x:
if list[list[x]] == list[x]:
duplication.append(list[x])
return True
else:
list[list[x]],list[x] = list[x],list[list[x]]
return False
#In this way, you don't need to open up space and reduce space complexity. Be the most perfect solution
Derivative topics:
What if the array cannot be modified?
1. Use an auxiliary array, but increase the auxiliary space of o (n)
2. Use the method of finding the number: between 1 and n, find the middle number m, divide the original array into two groups, 1 to m and m + 1 to n. In 1 to m, count the total number of occurrences of each number in the original array. If it is greater than m, then there are numbers repeated in 1 to m, and so on, similar to the dichotomy search to find duplicate values
