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.

思路：
从头开始遍历。分别设置两个累加器来表示前面整数的个数和后面0的个数，当a+b=nums.size()的时候遍历结束。

代码实现：

class Solution {
public:
void moveZeroes(vector<int>& nums) {
int n=nums.size();
int a=0;
int b=0;
while(a+b<n){
if(nums.at(a)==0){
nums.erase(nums.begin()+a);
nums.push_back(0);
b++;
}
else
a++;
}
}
};