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.

分析：i遍历数组，当i指向为非0时，且ji不同时，j后移，将j处的数改成i处的数，并使i处的数字为0，ij同步后移，

　　　　　　　　而当i指向为0时，只有i后移，j仍然指向0处

public void moveZeroes(int[] nums) {
        int i = 0, j = 0;
        for (i = 0; i < nums.length; i++) {
            if (nums[i] != 0) {
                if (j != i) {
                    nums[j] = nums[i];
                    nums[i] = 0;
                }
                j++;
            }
        }
    }