8.13

8.13

https://leetcode.com/problems/last-stone-weight/solutions/7027678/priority-queue-heap-solution-beat-100-of-other-submissions-runtime/?envType=problem-list-v2&envId=heap-priority-queue

https://leetcode.com/problems/two-sum/description/?envType=problem-list-v2&envId=hash-table


class Solution {
public:
    int lastStoneWeight(vector<int>& stones) {
        priority_queue<int> pq;

        for(int i : stones){
            pq.push(i);
        }

        while(pq.size() > 1){
            int a = pq.top(); pq.pop();
            int b = pq.top(); pq.pop();
            if(a != b){
                pq.push(abs(a-b));
            }
        }

        return pq.empty() ? 0 : pq.top();
    }
};

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int, vector<int>> hashTable;
        vector<int> result;

        for (int i = 0; i < nums.size(); i++) {
            hashTable[nums[i]].push_back(i);
        }

        for(int j=0; j<nums.size(); j++){
            int findNumberAddMillion = target - nums[j] + 100000000;
            int findNumber = target - nums[j];
            int findNumberIndexSecond;

            if (hashTable.find(findNumber) != hashTable.end() && !hashTable[findNumber].empty()){

                if (hashTable[findNumber][0] == j && hashTable[findNumber].size() > 1) {
                    findNumberIndexSecond = hashTable[findNumber][1];
                }else if (hashTable[findNumber][0] != j) {
                    findNumberIndexSecond = hashTable[findNumber][0];
                }else{
                    continue;
                }
                result.push_back(j);
                result.push_back(findNumberIndexSecond);
                break;
            }
        }
        return result;
    }
};