Javascript
共 5 篇文章
Description
Given an array of integers, return indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
Example:
Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].
0. My solution(Brute Force)
var twoSum = function(nums, target) {
for(let i = 0; i < nums.length; i++) {
for(let j = 0; j < nums.length; j++) {
if(nums[i] + nums[j] === target && i != j) {
return [i, j]
}
}
}
};
· Time complexity: O(n^2), For each element, I try to find its complement by looping through the rest of array which takes O(n)*O(n) time. Therefore, the time complexity is O(n^2).