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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_houri ≤ N), an ending hour (starting_houri < ending_houri ≤ N), and a corresponding efficiency (1 ≤ efficiencyi ≤ 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.
Input
- 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_houri , ending_houri , and efficiencyi
Output
- Line 1: The maximum number of gallons of milk that Bessie can product in the N hours
Sample Input
12 4 2 1 2 8 10 12 19 3 6 24 7 10 31 Sample Output 43
题目大意：一头奶牛现在要工作n小时，在这n小时里有m个任务。奶牛每完成一个任务后要休息r小时。给出这m个任务的开始时间、结束时间和得到的奶量。求在这m个任务中如何选择能得到最大的产奶量。
题目分析：
f[i] //表示1-i小时的最大产奶量a[i].r+=rest) 注意：在状态计算的时候也要往后算到f[n+rest]。 然后将这m个区间按照右端点进行排序(按左端点进行排序好像也可以，但那样计算方法也会不一样)。当第i小时没有完成某个任务产奶时，f[i]=f[i-1] //1一i小时的最大产奶量等于1一i-1小时的产奶量 2）当第i个小时完成了某些任务产奶时，即i==a[k].r（1<=k<=m），有两个选择(选择该任务和不选该任务),取最大值即可。f[i]=max(f[i-1],f[a[k].l]+a[k++].c)代码如下：
#include#include #include #include #include #include
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