packagemedium;

publicclassDesignHitCounter {

}

classHitCounter {

privateint[]times;

privateint[]hits;

privateintk;

publicHitCounter() {

k =300;

times =newint[k];

hits =newint[k];

}

publicvoidhit(inttimestamp) {

intindex =timestamp %k;

if (times[index] !=timestamp){

times[index] =timestamp;

hits[index] =1;

}else {

hits[index]++;

}

}

publicintgetHits(inttimestamp) {

inttotal =0;

for (inti =0;i <k;i++){

if (timestamp -times[i] <k){

total +=hits[i];

}

}

returntotal;

}

}

|370|[Range Addition](https://leetcode.com/problems/range-addition/)|[Solution](../../blob/master/MEDIUM/src/medium/RangeAddition.java)| O(n+k)|O(1)| Medium|

|366|[Find Leaves of Binary Tree](https://leetcode.com/problems/find-leaves-of-binary-tree/)|[Solution](../../blob/master/MEDIUM/src/medium/FindLeavesofBinaryTree.java)| O(n)|O(h) | Medium| DFS

|364|[Nested List Weight Sum II](https://leetcode.com/problems/nested-list-weight-sum-ii/)|[Solution](../../blob/master/MEDIUM/src/medium/NestedListWeightSumII.java)| O(n)|O(h) | Medium| DFS

|362|[Design Hit Counter](https://leetcode.com/problems/design-hit-counter/)|[Solution](../../blob/master/MEDIUM/src/medium/DesignHitCounter.java)| O(1) amortized|O(k) | Medium| Design

|359|[Logger Rate Limiter](https://leetcode.com/problems/logger-rate-limiter/)|[Solution](../../blob/master/EASY/src/easy/LoggerRateLimiter.java)| amortized O(1)|O(k) | Easy| HashMap

|350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/)|[Solution](../../blob/master/EASY/src/easy/IntersectionOfTwoArraysII.java)| O(m+n)|O((m+n)) could be optimized | Easy| HashMap, Binary Search

|349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/)|[Solution](../../blob/master/EASY/src/easy/IntersectionOfTwoArrays.java)| O(m+n)|O(min(m,n)) | Easy| Two Pointers, Binary Search