shunfurh 于 2017.01.03 15:07 提问

Drying

Description

It is very hard to wash and especially to dry clothes in winter. But Jane is a very smart girl. She is not afraid of this boring process. Jane has decided to use a radiator to make drying faster. But the radiator is small, so it can hold only one thing at a time.

Jane wants to perform drying in the minimal possible time. She asked you to write a program that will calculate the minimal time for a given set of clothes.

There are n clothes Jane has just washed. Each of them took ai water during washing. Every minute the amount of water contained in each thing decreases by one (of course, only if the thing is not completely dry yet). When amount of water contained becomes zero the cloth becomes dry and is ready to be packed.

Every minute Jane can select one thing to dry on the radiator. The radiator is very hot, so the amount of water in this thing decreases by k this minute (but not less than zero — if the thing contains less than k water, the resulting amount of water will be zero).

The task is to minimize the total time of drying by means of using the radiator effectively. The drying process ends when all the clothes are dry.

Input

The first line contains a single integer n (1 ≤ n ≤ 100 000). The second line contains ai separated by spaces (1 ≤ ai ≤ 109). The third line contains k (1 ≤ k ≤ 109).

Output

Output a single integer — the minimal possible number of minutes required to dry all clothes.

Sample Input

sample input #1
3
2 3 9
5

sample input #2
3
2 3 6
5
Sample Output

sample output #1
3

sample output #2
2

1个回答

devmiao      2017.01.03 18:39

POJ 3104 Drying 二分

poj 3104 Drying 二分答案

POJ 3104 Drying-二分答案

POJ - 3104 Drying 二分 ＋ 贪心

poj 3104 Drying 二分+基本数学

Drying Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 18921   Accepted: 4742 Description It is very hard to wash and especially to dry clothes in winter. Bu
POJ: Drying（二分、值最小化）

POJ3104-Drying

POJ 3104 Drying（二分搜索，最大化最小值）
Drying Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 11464   Accepted: 2967 Description It is very hard to wash and especially to dry clothes in winter.
Drying<二分，思维题>
Drying Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 16728   Accepted: 4238 Description It is very hard to wash and especially to dry clothes in winter.