题目:
Given an array nums and a value val, 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.
AC:
class Solution {
public int removeElement(int[] nums, int val) {
if (null == nums || 0 == nums.length) {
return 0;
}
int start = 0;
int end = nums.length - 1;
while (start <= end) {
if (val == nums[start]) {
int tmp = nums[start];
nums[start] = nums[end];
nums[end] = tmp;
end--;
}
else {
start++;
}
}
return start;
}
}