day-179.cpp

/*

  Teemo Attacking


In LOL world, there is a hero called Teemo and his attacking can make his enemy
Ashe be in poisoned condition. Now, given the Teemo's attacking ascending time
series towards Ashe and the poisoning time duration per Teemo's attacking, you
need to output the total time that Ashe is in poisoned condition.

You may assume that Teemo attacks at the very beginning of a specific time
point, and makes Ashe be in poisoned condition immediately.

Example 1:

Input: [1,4], 2
Output: 4
Explanation: At time point 1, Teemo starts attacking Ashe and makes Ashe be
poisoned immediately. This poisoned status will last 2 seconds until the end of
time point 2. And at time point 4, Teemo attacks Ashe again, and causes Ashe to
be in poisoned status for another 2 seconds. So you finally need to output 4.


Example 2:

Input: [1,2], 2
Output: 3
Explanation: At time point 1, Teemo starts attacking Ashe and makes Ashe be
poisoned. This poisoned status will last 2 seconds until the end of time
point 2. However, at the beginning of time point 2, Teemo attacks Ashe again who
is already in poisoned status. Since the poisoned status won't add up together,
though the second poisoning attack will still work at time point 2, it will stop
at the end of time point 3. So you finally need to output 3.


Note:

You may assume the length of given time series array won't exceed 10000.
You may assume the numbers in the Teemo's attacking time series and his
poisoning time duration per attacking are non-negative integers, which won't
exceed 10,000,000.
*/

// Simple O(N) solution
// Beats 98.39 % of cpp submissions.

class Solution {
   public:
    int findPoisonedDuration(vector<int>& timeSeries, int duration) {
        int N = timeSeries.size();
        if (N == 0) return 0;
        int totalDuration = duration;
        int endDurationTime = timeSeries[0] + duration - 1;

        for (int idx = 1; idx < N; idx++) {
            int nextEndDuraton = timeSeries[idx] + duration - 1;
            if (timeSeries[idx] > endDurationTime) {
                totalDuration += duration;
                endDurationTime = nextEndDuraton;
            } else if (nextEndDuraton >= endDurationTime) {
                totalDuration += (nextEndDuraton - endDurationTime);
                endDurationTime = nextEndDuraton;
            }
        }

        return totalDuration;
    }
};