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:
Input: nums =[1,3], n =6Output: 1 Explanation: Combinations of nums are[1], [3], [1,3], which form possible sums of:1, 3, 4. Now if we add/patch2to nums, the combinations are:[1], [2], [3], [1,3], [2,3], [1,2,3]. Possible sums are1, 2, 3, 4, 5, 6, which now covers the range[1, 6]. So we only need1patch.
Example 2:
Input: nums =[1,5,10], n =20Output: 2 Explanation: The two patches can be[2, 4].
Example 3:
Input: nums =[1,2,2], n =5Output: 0
struct Solution;
impl Solution {
fn min_patches(nums: Vec<i32>, n: i32) -> i32 {
let mut res = 0;
let mut miss: i64 = 1;
let mut i = 0;
while miss <= n as i64 {
if i < nums.len() && nums[i] as i64 <= miss {
miss += nums[i] as i64;
i += 1;
} else {
miss += miss;
res += 1;
}
}
res
}
}
#[test]
fn test() {
let nums = vec![1, 3];
let n = 6;
let res = 1;
assert_eq!(Solution::min_patches(nums, n), res);
let nums = vec![1, 5, 10];
let n = 20;
let res = 2;
assert_eq!(Solution::min_patches(nums, n), res);
let nums = vec![1, 2, 2];
let n = 5;
let res = 0;
assert_eq!(Solution::min_patches(nums, n), res);
}