Practice Problems

Problem of the Day: Integer Square Root — keep your streak alive!

Practice Problems — 1200-1600

#ProblemTopicsDifficulty
146 Sum of Divisors math number-theory 1400
149 Goldbach Split math number-theory 1400
150 Twin Prime Pairs math number-theory 1400
159 Last K Digits of a Power math 1400
162 Routes Across a Grid math combinatorics 1400
163 Catalan Number math combinatorics 1400
169 Last Digit of Fibonacci math 1400
182 Best Pairing greedy sorting 1400
185 Can You Reach the End greedy 1400
200 Find the Peak binary-search 1400
215 Cheapest Path Through the Grid dp 1400
220 Down the Triangle dp 1400
237 Any Cycle at All graphs union-find 1400
242 Count the Lakes bfs graphs 1400
243 The Largest Lake bfs graphs 1400
244 Escape the Maze bfs graphs 1400
253 Next Greater to the Right stack 1400
254 Days Until Warmer stack 1400
255 Stock Span stack 1400
269 Best Dot Product greedy sorting 1400
270 Worst Dot Product greedy sorting 1400
304 Days Apart math implementation 1400
324 Product of the Others prefix-sums 1400
345 The N-th Ugly Number math dp 1400
358 Round-Robin Printer math implementation 1400
408 The Infinite Digit String math 1400
418 Closest Pair Sum to Zero sorting two-pointers 1400
419 March to the Median math sorting 1400
452 The Two Missing Numbers math 1400
460 Two Equal Sets math greedy 1400
467 Stacked Range Additions prefix-sums 1400
468 How Many Intervals Cover X intervals prefix-sums 1400
474 Smallest Absent Positive implementation 1400
483 K Nearest Values sorting two-pointers 1400
484 Merged Timeline intervals sorting 1400
516 Range Sums in a Window divide-and-conquer fenwick 1400
636 Painting the Fence math combinatorics 1400
637 Counting Dice Rolls dp combinatorics 1400
740 Paint and Sum lazy-propagation segment-tree 1400
751 All Digits at Most Five digit-dp 1400
781 All Digits Even digit-dp 1400
855 All Digits at Most Three digit-dp 1400
858 Sum of Fourth Powers Modulo math 1400
888 All Digits at Least Five digit-dp 1400
80 Longest Palindromic Substring strings 1500
81 Count Palindromic Substrings strings 1500
96 Subarrays Summing to K prefix-sums 1500
97 Sum over All Subarrays math prefix-sums 1500
103 Shortest Sufficient Stretch sliding-window two-pointers 1500
108 Closest Pair Sum sorting two-pointers 1500