LeetCode 1486. XOR Operation in an Array

题目描述

Given an integer n and an integer start.

Define an array nums where nums[i] = start + 2*i (0-indexed) and n == nums.length.

Return the bitwise XOR of all elements of nums.

Example 1:

Input: n = 5, start = 0
Output: 8
Explanation: Array nums is equal to [0, 2, 4, 6, 8] where (0 ^ 2 ^ 4 ^ 6 ^ 8) = 8.
Where "^" corresponds to bitwise XOR operator.

Example 2:

Input: n = 4, start = 3
Output: 8
Explanation: Array nums is equal to [3, 5, 7, 9] where (3 ^ 5 ^ 7 ^ 9) = 8.

Constraints:

1 <= n <= 1000
0 <= start <= 1000
n == nums.length

题目思路

• 思路一、考察整数的异或运算

class Solution {
public:
    int xorOperation(int n, int start) {
        int res = start;
        int tmp = 0;
        for(int i = 1; i < n; ++i){
            tmp = start + 2 * i;
            res = res ^ tmp;
        }
        return res;
    }
};

总结展望