刷題283. Move Zeroes

一、題目說明

題目283. Move Zeroes，給定一組數，將該組數中的0移動末尾，其他數據相對位置不變。

二、我的解答

class Solution{
	public:
		void moveZeroes(vector<int>& nums){
			if(nums.size()<2){
				return;
			}
			int len = nums.size();

			int i=0,j=0;
			//i指向更新的位置,j指向非0元素
			while(i<len &&j<len){
				if(nums[j]==0){
					j++; 
				}else{
					nums[i] = nums[j];
					i++;
					j++;
				}
			}
			for(int t = i;t<len;t++){
				nums[t] = 0;
			}
		}
};

性能如下：

Runtime: 12 ms, faster than 97.09% of C++ online submissions for Move Zeroes.
Memory Usage: 9.5 MB, less than 87.50% of C++ online submissions for Move Zeroes.

三、優化措施

從左到右遍歷數組，統計0的個數，num[i]爲整數，則將其移動到nums[i-count]

class Solution{
	public:
		void moveZeroes(vector<int>& nums){
			int count = 0;
			for(int i=0;i<nums.size();i++){
				if(nums[i]==0){
					count++;
				}else if(count>0){
					nums[i-count] = nums[i];
					nums[i] = 0;
				}
			}	
		}
};

性能

Runtime: 12 ms, faster than 97.09% of C++ online submissions for Move Zeroes.
Memory Usage: 9.5 MB, less than 84.72% of C++ online submissions for Move Zeroes.