思路:
将用户到达时间及服务时间统一处理为秒,并按照到达时间排序,创建一个容量为k(窗口数)的优先队列,并将全部元素初始化为8*3600(8:00),优先队列内保存当前客户服务结束时间。依次处理按序到达的客户。
#include<cstdio>
#include<cstring>
#include<queue>
#include<algorithm>
#include<vector>
using namespace std;
struct customer
{
int time;
int service;
};
bool cmp(customer a,customer b){ return a.time < b.time; }
int main()
{
customer a[100001];
priority_queue<int,vector<int>,greater<int> > b;
int n,k;
int hour,minute,second,service;
double total = 0;
int count = 0;
scanf("%d%d",&n,&k);
for(int i=0; i<n;++i)
{
scanf("%d:%d:%d%d",&hour,&minute,&second,&service);
if((hour*3600+minute*60+second) <= (17*3600))
{
a[count].time = hour*3600+minute*60+second;
a[count].service = service*60;
count++;
}
}
sort(a,a+count,cmp);
for(int i=0;i<k;++i)
b.push(8*3600);
int j=0;
while(j<count)
{
int curtime;
curtime = b.top();
b.pop();
if(curtime < a[j].time)
b.push(a[j].time+a[j].service);
else
{
b.push(curtime+a[j].service);
total+=(curtime-a[j].time);
}
j++;
}
printf("%.1f",total/j/60);
}