diff --git a/leetcode/1705.Maximum-Number-of-Eaten-Apples/1705.Maximum Number of Eaten Apples.go b/leetcode/1705.Maximum-Number-of-Eaten-Apples/1705.Maximum Number of Eaten Apples.go new file mode 100644 index 00000000..a4ffd6cf --- /dev/null +++ b/leetcode/1705.Maximum-Number-of-Eaten-Apples/1705.Maximum Number of Eaten Apples.go @@ -0,0 +1,67 @@ +package leetcode + +import "container/heap" + +func eatenApples(apples []int, days []int) int { + h := hp{} + i := 0 + var ans int + for ; i < len(apples); i++ { + for len(h) > 0 && h[0].end <= i { + heap.Pop(&h) + } + if apples[i] > 0 { + heap.Push(&h, data{apples[i], i + days[i]}) + } + if len(h) > 0 { + minData := heap.Pop(&h).(data) + ans++ + if minData.left > 1 { + heap.Push(&h, data{minData.left - 1, minData.end}) + } + } + } + for len(h) > 0 { + for len(h) > 0 && h[0].end <= i { + heap.Pop(&h) + } + if len(h) == 0 { + break + } + minData := heap.Pop(&h).(data) + nums := min(minData.left, minData.end-i) + ans += nums + i += nums + } + return ans +} + +func min(a, b int) int { + if a < b { + return a + } + return b +} + +type data struct { + left int + end int +} + +type hp []data + +func (h hp) Len() int { return len(h) } +func (h hp) Less(i, j int) bool { return h[i].end < h[j].end } +func (h hp) Swap(i, j int) { h[i], h[j] = h[j], h[i] } + +func (h *hp) Push(x interface{}) { + *h = append(*h, x.(data)) +} + +func (h *hp) Pop() interface{} { + old := *h + n := len(old) + x := old[n-1] + *h = old[0 : n-1] + return x +} diff --git a/leetcode/1705.Maximum-Number-of-Eaten-Apples/1705.Maximum Number of Eaten Apples_test.go b/leetcode/1705.Maximum-Number-of-Eaten-Apples/1705.Maximum Number of Eaten Apples_test.go new file mode 100644 index 00000000..3b178c7a --- /dev/null +++ b/leetcode/1705.Maximum-Number-of-Eaten-Apples/1705.Maximum Number of Eaten Apples_test.go @@ -0,0 +1,46 @@ +package leetcode + +import ( + "fmt" + "testing" +) + +type question1705 struct { + para1705 + ans1705 +} + +// para 是参数 +type para1705 struct { + apples []int + days []int +} + +// ans 是答案 +type ans1705 struct { + ans int +} + +func Test_Problem1705(t *testing.T) { + + qs := []question1705{ + + { + para1705{[]int{1, 2, 3, 5, 2}, []int{3, 2, 1, 4, 2}}, + ans1705{7}, + }, + + { + para1705{[]int{3, 0, 0, 0, 0, 2}, []int{3, 0, 0, 0, 0, 2}}, + ans1705{5}, + }, + } + + fmt.Printf("------------------------Leetcode Problem 1705------------------------\n") + + for _, q := range qs { + _, p := q.ans1705, q.para1705 + fmt.Printf("【input】:%v 【output】:%v\n", p, eatenApples(p.apples, p.days)) + } + fmt.Printf("\n\n\n") +} diff --git a/leetcode/1705.Maximum-Number-of-Eaten-Apples/README.md b/leetcode/1705.Maximum-Number-of-Eaten-Apples/README.md new file mode 100644 index 00000000..6f4b9594 --- /dev/null +++ b/leetcode/1705.Maximum-Number-of-Eaten-Apples/README.md @@ -0,0 +1,124 @@ +# [1705. Maximum Number of Eaten Apples](https://leetcode-cn.com/problems/maximum-number-of-eaten-apples/) + +## 题目 + +There is a special kind of apple tree that grows apples every day for n days. On the ith day, the tree grows apples[i] apples that will rot after days[i] days, that is on day i + days[i] the apples will be rotten and cannot be eaten. On some days, the apple tree does not grow any apples, which are denoted by apples[i] == 0 and days[i] == 0. + +You decided to eat at most one apple a day (to keep the doctors away). Note that you can keep eating after the first n days. + +Given two integer arrays days and apples of length n, return the maximum number of apples you can eat. + +**Example 1**: + + Input: apples = [1,2,3,5,2], days = [3,2,1,4,2] + Output: 7 + Explanation: You can eat 7 apples: + - On the first day, you eat an apple that grew on the first day. + - On the second day, you eat an apple that grew on the second day. + - On the third day, you eat an apple that grew on the second day. After this day, the apples that grew on the third day rot. + - On the fourth to the seventh days, you eat apples that grew on the fourth day. + +**Example 2**: + + Input: apples = [3,0,0,0,0,2], days = [3,0,0,0,0,2] + Output: 5 + Explanation: You can eat 5 apples: + - On the first to the third day you eat apples that grew on the first day. + - Do nothing on the fouth and fifth days. + - On the sixth and seventh days you eat apples that grew on the sixth day. + +**Constraints:** + +- apples.length == n +- days.length == n +- 1 <= n <= 2 * 10000 +- 0 <= apples[i], days[i] <= 2 * 10000 +- days[i] = 0 if and only if apples[i] = 0. + +## 题目大意 + +有一棵特殊的苹果树，一连 n 天，每天都可以长出若干个苹果。在第 i 天，树上会长出 apples[i] 个苹果，这些苹果将会在 days[i] 天后（也就是说，第 i + days[i] 天时）腐烂，变得无法食用。也可能有那么几天，树上不会长出新的苹果，此时用 apples[i] == 0 且 days[i] == 0 表示。 + +你打算每天 最多 吃一个苹果来保证营养均衡。注意，你可以在这 n 天之后继续吃苹果。 + +给你两个长度为 n 的整数数组 days 和 apples ，返回你可以吃掉的苹果的最大数目。 + +## 解题思路 + +贪心算法和最小堆 + + - data中的end表示腐烂的日期，left表示拥有的苹果数量 + - 贪心:每天吃掉end最小但没有腐烂的苹果 + - 最小堆:构造类型为数组(数组中元素的类型为data)的最小堆 + +## 代码 + +```go +package leetcode + +import "container/heap" + +func eatenApples(apples []int, days []int) int { + h := hp{} + i := 0 + var ans int + for ; i < len(apples); i++ { + for len(h) > 0 && h[0].end <= i { + heap.Pop(&h) + } + if apples[i] > 0 { + heap.Push(&h, data{apples[i], i + days[i]}) + } + if len(h) > 0 { + minData := heap.Pop(&h).(data) + ans++ + if minData.left > 1 { + heap.Push(&h, data{minData.left - 1, minData.end}) + } + } + } + for len(h) > 0 { + for len(h) > 0 && h[0].end <= i { + heap.Pop(&h) + } + if len(h) == 0 { + break + } + minData := heap.Pop(&h).(data) + nums := min(minData.left, minData.end-i) + ans += nums + i += nums + } + return ans +} + +func min(a, b int) int { + if a < b { + return a + } + return b +} + +type data struct { + left int + end int +} + +type hp []data + +func (h hp) Len() int { return len(h) } +func (h hp) Less(i, j int) bool { return h[i].end < h[j].end } +func (h hp) Swap(i, j int) { h[i], h[j] = h[j], h[i] } + +func (h *hp) Push(x interface{}) { + *h = append(*h, x.(data)) +} + +func (h *hp) Pop() interface{} { + old := *h + n := len(old) + x := old[n-1] + *h = old[0 : n-1] + return x +} +``` \ No newline at end of file