330. Patching Array【M】【84】【leetcode】

Given a sorted positive integer array nums and an integer n, add/patch elements to the array such that any number in range

[1,
n]

inclusive can be formed by the sum of some elements in the array. Return the minimum number of patches required.

Example 1:

nums =

[1, 3]

, n =

6

Return

1

.

Combinations of nums are

[1], [3], [1,3]

, which form possible sums of:

1,
3, 4

.

Now if we add/patch

2

to nums, the combinations are:

[1],
[2], [3], [1,3], [2,3], [1,2,3]

.

Possible sums are

1, 2, 3, 4, 5, 6

, which now covers the range

[1,
6]

.

So we only need

1

patch.

Example 2:

nums =

[1, 5, 10]

, n =

20

Return

2

.

The two patches can be

[2, 4]

.

Example 3:

nums =

[1, 2, 2]

, n =

5

Return

0

.

Credits:

Special thanks to @dietpepsi for adding this problem and creating all test cases.

Subscribe to see which companies asked this question

class Solution(object):
def minPatches(self, nums, n):
res = 0
cur = 1
total = 1
i = 0
while total <= n:
if i < len(nums) and nums[i] <= total : #cur not in nums:
#res += 1
total += nums[i]
i += 1
else:
res += 1
total += total
#print nums,total
return res