495. Teemo Attacking

难度: Easy

题目描述

Our hero Teemo is attacking an enemy Ashe with poison attacks! When Teemo attacks Ashe, Ashe gets poisoned for a exactly duration seconds. More formally, an attack at second t will mean Ashe is poisoned during the inclusive time interval [t, t + duration - 1]. If Teemo attacks again before the poison effect ends, the timer for it is reset, and the poison effect will end duration seconds after the new attack.

You are given a non-decreasing integer array timeSeries, where timeSeries[i] denotes that Teemo attacks Ashe at second timeSeries[i], and an integer duration.

Return the total number of seconds that Ashe is poisoned.

 

Example 1:

Input: timeSeries = [1,4], duration = 2
Output: 4
Explanation: Teemo's attacks on Ashe go as follows:
- At second 1, Teemo attacks, and Ashe is poisoned for seconds 1 and 2.
- At second 4, Teemo attacks, and Ashe is poisoned for seconds 4 and 5.
Ashe is poisoned for seconds 1, 2, 4, and 5, which is 4 seconds in total.

Example 2:

Input: timeSeries = [1,2], duration = 2
Output: 3
Explanation: Teemo's attacks on Ashe go as follows:
- At second 1, Teemo attacks, and Ashe is poisoned for seconds 1 and 2.
- At second 2 however, Teemo attacks again and resets the poison timer. Ashe is poisoned for seconds 2 and 3.
Ashe is poisoned for seconds 1, 2, and 3, which is 3 seconds in total.

 

Constraints:

• 1 <= timeSeries.length <= 104
• 0 <= timeSeries[i], duration <= 107
• timeSeries is sorted in non-decreasing order.

解题思路

代码实现

解决方案

java

class Solution {
    public int findPoisonedDuration(int[] timeSeries, int duration) {

        int ans = 0;
        int end = -1;
        int n = timeSeries.length;
        for (int i = 0; i < n; i++) {
            if (end == -1) {
                end = timeSeries[i] + duration - 1;
                ans = duration;
                continue;
            }
            if (timeSeries[i] > end) {
                end = timeSeries[i] + duration - 1;
                ans += duration;
            } else {
                int d = end - timeSeries[i] + 1;
                if (timeSeries[i] + duration - 1 <= end) {
                    continue;
                }
                end = timeSeries[i] + duration - 1;
                ans = ans + duration - d;
            }

        }

        return ans;

    }
}