2061. Milking Time

单点时限: 2.0 sec

内存限制: 256 MB

Bessie is such a hard-working cow. In fact, she is so focused on maximizing her productivity that she decides to schedule her next N (1 <= N <= 1,000,000) hours (conveniently labeled 0..N-1) so that she produces as much milk as possible.

Farmer John has a list of M (1 <= M <= 1,000) possibly overlapping intervals in which he is available for milking. Each interval i has a starting hour (0 <= starting_hour_i < N), an ending hour (starting_hour_i < ending_hour_i <= N), and a corresponding efficiency

(1 <= efficiency_i <= 1,000,000) which indicates how many gallons of milk that he can get out of Bessie in that interval. Farmer John starts and stops milking at the beginning of the starting hour and ending hour, respectively. When being milked, Bessie must be milked

through an entire interval.

Even Bessie has her limitations, though. After being milked during any interval, she must rest R (1 <= R <= N) hours before she can start milking again. Given Farmer Johns list of intervals, determine the maximum amount of milk that Bessie can produce in the N hours.

输入格式

  • Line 1: Three space-separated integers: N, M, and R

  • Lines 2..M+1: Line i+1 describes FJ’s ith milking interval withthree space-separated integers: starting_hour_i, ending_hour_i, and efficiency_i

输出格式

  • Line 1: The maximum number of gallons of milk that Bessie can product in the N hours

样例

Input
12 4 2
1 2 8
10 12 19
3 6 24
7 10 31
INPUT DETAILS:
Bessie wants to schedule the next 12 hours; Farmer John has four intervals in which he can milk her; Bessie must rest 2 hours after every milking. The first interval lasts from hour 1 to hour 2, the second from hour 10 to hour 12, the third from hour 3 to hour 6,and the fourth from hour 7 to hour 10. Farmer John can get 8, 19,24, and 31 gallons of milk, respectively, from Bessie in those intervals.
Output
43
OUTPUT DETAILS:
If Bessie uses the first interval, she cannot use the third becauseshe needs 2 hours of rest. If she uses the second, she cannot use the fourth. Lastly, if she uses the third, she cannot use the fourth. The best situation is choosing the second and third intervals,producing 43 gallons of milk.

14 人解决,23 人已尝试。

15 份提交通过,共有 54 份提交。

5.8 EMB 奖励。

创建: 13 年,2 月前.

修改: 3 年,6 月前.

最后提交: 2 月,3 周前.

来源: USACO

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