| 1. Group Anagrams |
sort each word + maintain a hashmap of strings |
M |
| 2. Subarray Product Less Than K |
Two Pointers + count += right - left + 1 |
M |
| 3. Overlapping Rectangle |
two rectangles dont overlap when one side is out of reach of other from left & right |
E |
| 4. UglyNumber 2 |
Use a set or pq to revaluate the min each time, set.pb(currX {2,3,5} ), set.erase(curr)
DP idea - since each number can be generated from former ugly numbers by multiplying 2,3,5 (maintain pointers at 2,3,5) and increment accordingly |
M |
| 5. RunLengthEncoding |
2 pointers: r - find similiar items, l - update |
M |
| 6. GCD Strings |
str1+str2 == str2+str1 : gcd of strs = gcd of len |
M |
| 7. MthPosition |
(K+M-1)%N == 0 ? N : (K+M-1)%N |
B |
| 8. DecodeWays |
DP If curr idx valid : numWays[i] += numWays[i+1] :
idx + (idx+1) forms a valid combo : numWays[i] += numWays[i+2] |
M |
| 9. ID pattern |
REDO |
? |
| 10. Find max 10 numbers in a list having 10M entries |
An array of top 10 |
O |
| 11. Missing Numbers |
use indices as a measure (-1* if found ) |
M |
| 12. TotalSquaresChess |
(n*(n+1)*((2*n)+1))/6 |
B |
| 13. Decode String |
Simple Recursion |
M |
| 14. MinSizeSubarray |
Classic 2 pointers |
M |
| 15. ArrayPairs |
if sum of modulos is div then nums are also div |
M |
