Given an array, rotate the array to the right by k steps, where k is non-negative.
Example 1:
Input:[1,2,3,4,5,6,7]
and k = 3 Output:[5,6,7,1,2,3,4]
Explanation: rotate 1 steps to the right:[7,1,2,3,4,5,6]
rotate 2 steps to the right:[6,7,1,2,3,4,5]
rotate 3 steps to the right:[5,6,7,1,2,3,4]
Example 2:
Input: [-1,-100,3,99]
and k = 2
Output: [3,99,-1,-100]
Explanation:
rotate 1 steps to the right: [99,-1,-100,3]
rotate 2 steps to the right: [3,99,-1,-100]
Note:
- Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
- Could you do it in-place with O(1) extra space
题目链接:https://leetcode.com/problems/rotate-array/
class Solution {
public:
void rotate(vector<int>& nums, int k) {
while(k>0)
{
int t=nums.back();
nums.pop_back();
nums.insert(nums.begin(),t);
k--;
}
}
};
复习一下vector的erase()用法
#include<bits/stdc++.h>
using namespace std;
int main()
{
vector<int> v;
for(int i=0;i<6;i++)
v.emplace_back(i);
v.erase(v.begin(),v.begin()+2);
for(int i=0;i<v.size();i++)
cout<<v[i]<<endl;
return 0;
}