07/13/2021

[001] 1. Two Sum

[002] 1041. Robot Bounded in Circle

[003] 200. Number of Islands

[004] 146. LRU cache

[005] 56. Merge Intervals ***

// sort intervals[][] by the increasing order of index 0
Arrays.sort(intervals, (a, b) -> a[0] - b[0]);

 

[006] 121. Best Time to Buy and Sell Stock