- 题目:
- 蔬菜配送,求派送完成的最小时间
- 限制:
- 一个小区只能有一个人派送
- 每个人只能派送连续的几个小区
- 输入: 第一行是派送人数,第二行社区数,第三行每个社区所花时间
- 3
- 5
- 1 1 6 3 1
- 结果:
- 一个人派送1+1,一个人派送6,一个人派送3+1,至少耗时6
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Scanner;
public class Demo {
private static int deliver(int num, int[] communities) {
if (communities.length == 0) {
return 0;
}
if (num >= communities.length) {
Arrays.sort(communities);
return communities[communities.length - 1];
}
int max = communities[communities.length - 1];
PriorityQueue<Node> nodeQueue = new PriorityQueue<>(Comparator.comparing(node -> node.sumTime));
Node item = new Node();
for (int i = 0; i < communities.length - 1; i++) {
int value = communities[i];
Node node = new Node(i, value);
if (value > max) {
max = value;
}
item.next = node;
item = node;
node.sumTime = communities[i] + communities[i + 1];
nodeQueue.add(node);
}
item.next = new Node(communities.length - 1, communities[communities.length - 1]);
int[] merged = new int[communities.length];
for (int i = 0; i < communities.length - num; ) {
Node node = nodeQueue.poll();
if (merged[node.index] == 1) {
continue;
}
merged[node.next.index] = 1;
node.time = node.sumTime;
node.next = node.next.next;
if (node.next != null) {
node.sumTime = node.sumTime + node.next.time;
}
nodeQueue.offer(node);
max = Math.max(max, node.time);
i++;
}
return max;
}
static class Node {
int index;
int time;
int sumTime;
Node next;
public Node(int index, int time) {
this.index = index;
this.time = time;
}
public Node() {
}
}
public static void main(String[] args) {
Scanner cin = new Scanner(System.in, StandardCharsets.UTF_8.name());
int num = cin.nextInt();
int communitiesCnt = cin.nextInt();
int[] communities = new int[communitiesCnt];
for (int i = 0; i < communitiesCnt; i++) {
communities[i] = cin.nextInt();
}
cin.close();
System.out.println(deliver(num, communities));
}
}