Problems

3,848+ problems · 928 Easy · 2014 Medium · 906 Hard

Title	Solution	Practice	Difficulty	Companies	Topics
451. Sort Characters By Frequency	Solution	Solve	Medium	Accenture+16	Bucket Sort Counting+4
452. Minimum Number of Arrows to Burst Balloons	Solution	Solve	Medium	Amazon+9	Array Greedy+1
453. Minimum Moves to Equal Array Elements	Solution	Solve	Medium	Amazon+7	Array Math
454. 4Sum II	Solution	Solve	Medium	Amazon+2	Array Hash Table
455. Assign Cookies	Solution	Solve	Easy	Accenture+8	Array Greedy+2
456. 132 Pattern	Solution	Solve	Medium	Amazon+9	Array Binary Search+3
457. Circular Array Loop	Solution	Solve	Medium	Amazon+3	Array Hash Table+1
458. Poor Pigs	Solution	Solve	Hard	Google	Combinatorics Dynamic Programming+1
459. Repeated Substring Pattern	Solution	Solve	Easy	Amazon+7	String String Matching
460. LFU Cache	Solution	Solve	Hard	Amazon+30	Design Doubly-Linked List+2
461. Hamming Distance	Solution	Solve	Easy	Amazon+4	Bit Manipulation
462. Minimum Moves to Equal Array Elements II	Solution	Solve	Medium	Amazon+4	Array Math+1
463. Island Perimeter	Solution	Solve	Easy	Amazon+9	Array Breadth-First Search+2
464. Can I Win	Solution	Solve	Medium	Amazon+4	Bit Manipulation Bitmask+4
465. Optimal Account Balancing	Solution	Solve	Hard	Affirm+10	Array Backtracking+3
466. Count The Repetitions	Solution	Solve	Hard	Google	Dynamic Programming String
467. Unique Substrings in Wraparound String	Solution	Solve	Medium	Google+1	Dynamic Programming String
468. Validate IP Address	Solution	Solve	Medium	Adobe+12	String
469. Convex Polygon	Solution	Solve	Medium	Google	Array Geometry+1
470. Implement Rand10() Using Rand7()	Solution	Solve	Medium	Bloomberg+6	Math Probability and Statistics+2
471. Encode String with Shortest Length	Solution	Solve	Hard	Google	Dynamic Programming String
472. Concatenated Words	Solution	Solve	Hard	Amazon+4	Array Depth-First Search+3
473. Matchsticks to Square	Solution	Solve	Medium	Amazon+8	Array Backtracking+3
474. Ones and Zeroes	Solution	Solve	Medium	Amazon+4	Array Dynamic Programming+1
475. Heaters	Solution	Solve	Medium	Adobe+11	Array Binary Search+2
476. Number Complement	Solution	Solve	Easy	Cloudera+4	Bit Manipulation
477. Total Hamming Distance	Solution	Solve	Medium	Apple+3	Array Bit Manipulation+1
478. Generate Random Point in a Circle	Solution	Solve	Medium	Leap Motion+1	Geometry Math+2
479. Largest Palindrome Product	Solution	Solve	Hard	Yahoo	Enumeration Math
480. Sliding Window Median	Solution	Solve	Hard	Amazon+9	Array Hash Table+2
481. Magical String	Solution	Solve	Medium	Amazon+2	String Two Pointers
482. License Key Formatting	Solution	Solve	Easy	Amazon+1	String
483. Smallest Good Base	Solution	Solve	Hard	Amazon+2	Binary Search Math
484. Find Permutation	Solution	Solve	Medium	Google	Array Greedy+2
485. Max Consecutive Ones	Solution	Solve	Easy	Accenture+12	Array
486. Predict the Winner	Solution	Solve	Medium	Amazon+6	Array Dynamic Programming+3
487. Max Consecutive Ones II	Solution	Solve	Medium	Bloomberg+4	Array Dynamic Programming+1
488. Zuma Game	Solution	Solve	Hard	Amazon+6	Breadth-First Search Dynamic Programming+3
489. Robot Room Cleaner	Solution	Solve	Hard	Amazon+7	Backtracking Interactive
490. The Maze	Solution	Solve	Medium	Amazon+13	Array Breadth-First Search+2
491. Non-decreasing Subsequences	Solution	Solve	Medium	Amazon+2	Array Backtracking+2
492. Construct the Rectangle	Solution	Solve	Easy	Amazon+1	Math
493. Reverse Pairs	Solution	Solve	Hard	Adobe+8	Array Binary Indexed Tree+5
494. Target Sum	Solution	Solve	Medium	Amazon+10	Array Backtracking+1
495. Teemo Attacking	Solution	Solve	Easy	Amazon+4	Array Simulation
496. Next Greater Element I	Solution	Solve	Easy	Accenture+16	Array Hash Table+2
497. Random Point in Non-overlapping Rectangles	Solution	Solve	Medium	Google+1	Array Binary Search+5
498. Diagonal Traverse	Solution	Solve	Medium	Amazon+11	Array Matrix+1
499. The Maze III	Solution	Solve	Hard	Google	Array Breadth-First Search+6
500. Keyboard Row	Solution	Solve	Easy	Amazon+3	Array Hash Table+1