remove duplicates from array in-place: | use two pointers, one for traversal, one for insertion. | | max profit from stocks: | sum all consecutive negative difs. | | find pivot: | calculate what the sum of all previous elements needs to be, based on the total value of the list. use float division! | | isomorphic strings: | two hashes. one to store maps, one to store ending chars. if you see a char that is in the map, and it goes to a different character, return false. if you see a new char that goes to a char that's already mapped to, return false. | | reverse linked list: | pun ch wac nicoin coinip pic cin w pai