Leetcode495 Teemo Attacting

//  C++

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.

题目大意是给出Teemo攻击时刻表，Teemo每次攻击可以使Ashe在监狱待duration时间，攻击效果不能累加，即若攻击时Ashe已经在监狱中，则从当前时间从新开始使Ashe在监狱中待duration时间，输出Ashe一共在监狱中待的时间。

思路：设置标记位sign记录上次攻击可以使Ashe在监狱中待到哪一时刻，与本次攻击的时刻比较，若本次攻击时刻大于上次攻击后Ashe出狱时间，则Ashe在监狱待满一个duration，否则Ashe还未出狱就又被攻击，未待满一个duration变从新计时，所以在监狱中待的时间为duration减去相差的时间。

#include<iostream>
#include<vector>

using namespace std;

int findPoisonedDuration(vector<int>& timeSeries, int duration) {
	int res = 0,i;
	int sign = timeSeries[0]+duration;
	for(i = 1;i<timeSeries.size();i++){
		if(timeSeries[i]>=sign)
			res += duration;
		else
			res += duration-(sign-timeSeries[i]);
		sign = timeSeries[i] + duration;
	}
	return res+sign-timeSeries[i-1];
 }

int main(){	
	int a[] = {1,2,3,4,5};
	vector<int> v(a,a+5);
	cout<<findPoisonedDuration(v,5)<<endl;
	return 1;
}