Python: Find the first missing positive integer that does not exist in a given list
Python Basic - 1: Exercise-80 with Solution
Write a Python program to find the first missing positive integer that does not exist in a given list.
Sample Solution:
Python Code:
def first_missing_number(nums):
if len(nums) == 0:
return 1
nums.sort()
smallest_int_num = 0
for i in range(len(nums) - 1):
if nums[i] <= 0 or nums[i] == nums[i + 1]:
continue
else:
if nums[i + 1] - nums[i] != 1:
smallest_int_num = nums[i] + 1
return smallest_int_num
if smallest_int_num == 0:
smallest_int_num = nums[-1] + 1
return smallest_int_num
print(first_missing_number([2, 3, 7, 6, 8, -1, -10, 15, 16]))
print(first_missing_number([1, 2, 4, -7, 6, 8, 1, -10, 15]))
print(first_missing_number([1, 2, 3, 4, 5, 6, 7]))
print(first_missing_number([-2, -3, -1, 1, 2, 3]))
Sample Output:
4 3 8 4
Flowchart:

Python Code Editor:
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Previous: Write a Python program to compute the largest product of three integers from a given list of integers.
Next: Write a Python program to randomly generate a list with 10 even numbers between 1 and 100 inclusive.
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