function fibonacci(n) {
if (n <= 1) return n;
return fibonacci(n - 1) + fibonacci(n - 2);
}function binarySearch(arr, target) {
let left = 0;
let right = arr.length - 1;
while (left <= right) {
const mid = Math.floor((left + right) / 2);
if (arr[mid] === target) return mid;
if (arr[mid] < target) left = mid + 1;
else right = mid - 1;
}
return -1;
}function mergeSort(arr) {
if (arr.length <= 1) return arr;
const mid = Math.floor(arr.length / 2);
const left = mergeSort(arr.slice(0, mid));
const right = mergeSort(arr.slice(mid));
return merge(left, right);
}
function merge(left, right) {
const result = [];
let i = 0, j = 0;
while (i < left.length && j < right.length) {
if (left[i] < right[j]) {
result.push(left[i++]);
} else {
result.push(right[j++]);
}
}
return [...result, ...left.slice(i), ...right.slice(j)];
}function dfs(graph, start, visited = new Set()) {
visited.add(start);
console.log(start);
for (const neighbor of graph[start]) {
if (!visited.has(neighbor)) {
dfs(graph, neighbor, visited);
}
}
return visited;
}Your personalized online notebook
for everything LeetCode
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Repcode combines intelligent tracking, AI assistance, and proven learning techniques to help you master algorithms and data structures.
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- Import problem sets directly from Leetcode
Algorithm Problems
6 problems| Problem Name | Difficulty | Type |
|---|---|---|
| Two Sum | Easy | Review |
| Valid Parentheses | Easy | Learning |
| Merge Two Sorted Lists | Easy | New |
| Maximum Subarray | Medium | Review |
| LRU Cache | Medium | Learning |
| Merge k Sorted Lists | Hard | New |
Solve problems with our custom all-in-one interface
Our integrated coding environment makes it easy to understand, solve, and review Leetcode problems all in one place.
- Split-panel interface with problem description and code editor
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- Support for multiple programming languages
Two Sum
Problem Description
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
You can return the answer in any order.
Example 1:
Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].
Example 2:
Input: nums = [3,2,4], target = 6
Output: [1,2]
Constraints:
2 <= nums.length <= 104-109 <= nums[i] <= 109-109 <= target <= 109- Only one valid answer exists.
/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
function twoSum(nums, target) {
// Your code here
}Spatial Repitition Review
Each day, solve only the problems you need to so your brain learns new strategies and reinforces key concepts in the most effective way possible.
- Track your daily study streak and build consistency
- See which problems are due for review today
- Monitor your progress with beautiful visualizations
- Get personalized recommendations based on your performance
Study Dashboard
Current Streak
Due Today
Due Problems
Due Today
12 problemsTwo Sum
Valid Parentheses
Merge Two Sorted Lists
Maximum Subarray
LRU Cache
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