330. Patching Array
Description
Given a sorted integer array nums
and an integer n
, add/patch elements to the array such that any number in the 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:
Input: nums = [1,3], n = 6 Output: 1 Explanation: 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:
Input: nums = [1,5,10], n = 20 Output: 2 Explanation: The two patches can be [2, 4].
Example 3:
Input: nums = [1,2,2], n = 5 Output: 0
Constraints:
1 <= nums.length <= 1000
1 <= nums[i] <= 104
nums
is sorted in ascending order.1 <= n <= 231 - 1
Solutions
Solution: Greedy
- Time complexity: O(n)
- Space complexity: O(1)
JavaScript
js
/**
* @param {number[]} nums
* @param {number} n
* @return {number}
*/
const minPatches = function (nums, n) {
let result = (index = currentRange = 0);
while (currentRange < n) {
if (index < nums.length && currentRange + 1 >= nums[index]) {
currentRange += nums[index];
index += 1;
continue;
}
currentRange += currentRange + 1;
result += 1;
}
return result;
};