#!/usr/bin/env python

# encoding: utf-8

# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# Copyright (c) 2020-2022 Vladimir Shurygin. All rights reserved.

# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

"""

Given an array of non-negative integers, you are initially positioned at the first index of the array.

Each element in the array represents your maximum jump length at that position.

Determine if you are able to reach the last index.

Example 1:

Input: [2,3,1,1,4]

Output: true

Explanation: Jump 1 step from index 0 to 1, then 3 steps to the last index.

Example 2:

Input: [3,2,1,0,4]

Output: false

Explanation: You will always arrive at index 3 no matter what. Its maximum

jump length is 0, which makes it impossible to reach the last index.

"""

from typing import List

def can_jump(nums: List[int]) -> bool:

"""greedy algorithm"""

_len = len(nums)

state = [False] * _len

state[0] = True

for i in range(_len):

if state[i]:

val = nums[i]

if i + val >= _len - 1:

return True

state[i + 1:i + 1 + val] = [True] * val

return state[_len - 1]

if __name__ == '__main__':

test_cases = [

([1, 2, 3], True),

([3, 2, 1, 0, 4], False),

([2, 0], True),

([2, 5, 0, 0], True),

]

cnt = 0

for test_case in test_cases:

params = test_case[:-1]

expected = test_case[-1]

actual = can_jump(*params)

is_correct = actual == expected

cnt += 1

print('.', end='')

if not is_correct:

print(f'\n{params} => (actual={actual}) != (expected={expected})')

print(f'\nchecked {cnt} tests')