DSA

Left Rotate Array by One

Arrays. Time O(n), Space O(1).

August 8, 2026
DSAArraysLeetCodePractice

Given an integer array nums, rotate the array to the left by one.

Input: nums = [1, 2, 3, 4, 5]

Output: [2, 3, 4, 5, 1]

cpp
class Solution {
public:
    void rotateArrayByOne(vector<int>& nums) {
        int n = nums.size();
        int firstEle = nums[0];

        for(int i=1;i<n;i++){
            nums[i-1] = nums[i];
        }
        nums[n-1] = firstEle;
    }
};

Time Complexity: O(n)

Space Complexity: O(1)

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