Remove Element
描述
Given an array and a value, remove all instances of that value in-place and return the new length.
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
The order of elements can be changed. It doesn't matter what you leave beyond the new length.
Example:
Given nums = [3,2,2,3], val = 3,
Your function should return length = 2, with the first two elements of nums being 2.
题解
package algorithms
//Given an array and a value, remove all instances of that value in place and return the new length.
//
//Do not allocate extra space for another array, you must do this in place with constant memory.
//
//The order of elements can be changed. It doesn't matter what you leave beyond the new length.
//
//Example:
//Given input array nums = [3,2,2,3], val = 3
//
//Your function should return length = 2, with the first two elements of nums being 2.
// ???
func removeElement(nums []int, val int) int {
i, n := 0, len(nums)
for i < n {
if nums[i] == val {
n--
nums[i] = nums[n]
} else {
i++
}
}
return n
}