[Swift]LeetCode1176. 健身計劃評估 | Diet Plan Performance

★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★
➤微信公衆號：爲敢（WeiGanTechnologies）
➤博客園地址：山青詠芝（https://www.cnblogs.com/strengthen/）
➤GitHub地址：https://github.com/strengthen/LeetCode
➤原文地址：http://www.javashuo.com/article/p-xkbhczmc-hz.html 
➤若是連接不是山青詠芝的博客園地址，則多是爬取做者的文章。
➤原文已修改更新！強烈建議點擊原文地址閱讀！支持做者！支持原創！
★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★

A dieter consumes calories[i] calories on the i-th day.  For every consecutive sequence of k days, they look at T, the total calories consumed during that sequence of k days:

• If T < lower, they performed poorly on their diet and lose 1 point; 
• If T > upper, they performed well on their diet and gain 1 point;
• Otherwise, they performed normally and there is no change in points.

Return the total number of points the dieter has after all calories.length days.

Note that: The total points could be negative.

 

Example 1:

Input: calories = [1,2,3,4,5], k = 1, lower = 3, upper = 3
Output: 0
Explaination: calories[0], calories[1] < lower and calories[3], calories[4] > upper, total points = 0.

Example 2:

Input: calories = [3,2], k = 2, lower = 0, upper = 1
Output: 1
Explaination: calories[0] + calories[1] > upper, total points = 1.

Example 3:

Input: calories = [6,5,0,0], k = 2, lower = 1, upper = 5
Output: 0
Explaination: calories[0] + calories[1] > upper, calories[2] + calories[3] < lower, total points = 0.

 

Constraints:

• 1 <= k <= calories.length <= 10^5
• 0 <= calories[i] <= 20000
• 0 <= lower <= upper

---

你的好友是一位健身愛好者。前段日子，他給本身制定了一份健身計劃。如今想請你幫他評估一下這份計劃是否合理。

他會有一份計劃消耗的卡路里表，其中 calories[i] 給出了你的這位好友在第 i 天須要消耗的卡路里總量。

計劃的統計週期一般是 k 天，你須要計算他在每一段連續的 k 天內消耗的總卡路里 T：

• 若是 T < lower，那麼這份計劃相對糟糕，並失去 1 分； 
• 若是 T > upper，那麼這份計劃相對優秀，並得到 1 分；
• 不然，這份計劃普普統統，分值不作變更。

請返回統計完全部 calories.length 天后獲得的總分做爲評估結果。

注意：總分多是負數。

 

示例 1：

輸入：calories = [1,2,3,4,5], k = 1, lower = 3, upper = 3
輸出：0
解釋：calories[0], calories[1] < lower 而 calories[3], calories[4] > upper, 總分 = 0.

示例 2：

輸入：calories = [3,2], k = 2, lower = 0, upper = 1
輸出：1
解釋：calories[0] + calories[1] > upper, 總分 = 1.

示例 3：

輸入：calories = [6,5,0,0], k = 2, lower = 1, upper = 5
輸出：0
解釋：calories[0] + calories[1] > upper, calories[2] + calories[3] < lower, 總分 = 0.

 

提示：

• 1 <= k <= calories.length <= 10^5
• 0 <= calories[i] <= 20000
• 0 <= lower <= upper

---

Runtime: 220 ms

Memory Usage: 22.5 MB

 1 class Solution {
 2     func dietPlanPerformance(_ calories: [Int], _ k: Int, _ lower: Int, _ upper: Int) -> Int {
 3         var n:Int = calories.count
 4         var sum:Int = 0
 5         var ans:Int = 0
 6         for i in 0..<n
 7         {
 8             sum += calories[i]
 9             if i >= k
10             {
11                 sum -= calories[i-k]
12             }
13             if i >= k-1
14             {
15                 if sum > upper
16                 {
17                     ans += 1
18                 }
19                 else if sum < lower
20                 {
21                     ans -= 1
22                 }
23             }
24         }
25         return ans
26     }
27 }

---

224ms

 

 1 class Solution {
 2     func dietPlanPerformance(_ calories: [Int], _ k: Int, _ lower: Int, _ upper: Int) -> Int {
 3         guard calories.count > 0 && k >= 1 else { return 0 }
 4                 
 5         var res = 0
 6         var sum = 0
 7         
 8         var i = -1
 9         var j = 0
10         for j in 0..<calories.count {
11             sum += calories[j]
12 
13             if j - i > k {
14                 i += 1
15                 sum -= calories[i]                
16             }
17 
18             if j - i < k { continue }
19             
20             if sum < lower { res -= 1 }
21             else if sum > upper { res += 1 }   
22         }
23         
24         return res
25     }
26 }

---

228ms

 1 class Solution {
 2     func dietPlanPerformance(_ calories: [Int], _ k: Int, _ lower: Int, _ upper: Int) -> Int {
 3         
 4         var i = 0 
 5         var result = 0
 6         var sum = 0
 7         while i < calories.count {
 8             sum += calories[i]
 9             if i < k { 
10                 if i == k - 1 {
11                     if sum > upper { result += 1 }
12                     if sum < lower { result -= 1 }
13                 }
14                 i += 1
15                 continue 
16             } else {
17                 // print(sum)
18                 sum -= calories[i - k]
19             }
20             if sum > upper { result += 1 }
21             if sum < lower { result -= 1 }
22             i += 1
23         }
24         return result
25     }
26 }

---

232ms

 1 class Solution {
 2     func dietPlanPerformance(_ calories: [Int], _ k: Int, _ lower: Int, _ upper: Int) -> Int {
 3         guard calories.count >= k else {
 4             return 0
 5         }
 6         func getScore(_ costCalories:  Int)  -> Int {
 7             if costCalories < lower {
 8                 return -1
 9             }
10             if  costCalories > upper {
11                 return 1
12             }
13             return 0
14         }
15         var ans = 0
16         var i = 0
17         var tempCalories = 0
18         while i < k {
19             tempCalories += calories[i]
20             i += 1
21         }
22         ans += getScore(tempCalories)
23         while i < calories.count {
24             tempCalories += (calories[i] - calories[i -  k])
25             ans += getScore(tempCalories)
26             i += 1
27         }
28         return ans
29     }
30 }

---

236ms

 1 class Solution {
 2     func dietPlanPerformance(_ calories: [Int], _ k: Int, _ lower: Int, _ upper: Int) -> Int {
 3         var totalPoints = 0
 4         var preKSum: Int? = nil
 5         for i in k-1 ..< calories.count {
 6             if var kSum = preKSum {
 7                 preKSum = kSum - calories[i-k] + calories[i]
 8             } else {
 9                 preKSum = calories[0..<k].reduce(0,+)
10             }
11             
12             if preKSum! < lower {
13                 totalPoints -= 1
14             } else if preKSum! > upper {
15                 totalPoints += 1
16             }
17         }
18         
19         return totalPoints
20     }
21 }