leetcode - Move Zeroes

leetcode - Move Zeroes

Given an array

nums

, write a function to move all

0

's to the end of it while maintaining the relative order of the non-zero elements.

For example, given

nums = [0, 1, 0, 3, 12]

, after calling your function,

nums

should be

[1, 3, 12, 0, 0]

.

Note:

You must do this in-place without making a copy of the array.

Minimize the total number of operations.

class Solution {
public:
void moveZeroes(vector<int>& nums) {
int pos = -1, i = 0;
while(i<nums.size()){
if(nums[i] != 0){
nums[++pos] = nums[i];
}
i++;
}
while(pos+1<nums.size()){
nums[++pos]=0;
}
}
};

思路：先把非零的数排到前面，并记录非零数最后的位置，然后把后面的其他数字都设置为0即可。

时间复杂度O(n), 空间复杂度 O(1)