Dp:miking time (POJ 3616)

2015-09-21

　　　　　　　　　　　　　　

Milking cows

The main idea is this Bessie cow milk is very diligent, a farmer has a timetable, in n time divided into m time period, each time period Bessie will always produce milk, and then have a certain benefit, and Bessie milk to rest two hours.

This is a very simple DP, because the interval is not duplicated, so we just have to line up, and then from the first time period to the last time period

State transition equation:

DP[I][J]=DP[I-1][J] j<i;

Dp[i][i]=max (Dp[i][i],dp[i][j]+list[i].eff); J<i

It's very simple, I did this problem for two hours????

Why??? Because I'm getting the wrong line!

The code starts with the 1001*1001 matrix, the time is 0ms, but the memory to use 7000 +, with the rolling array time to 16ms, but the memory becomes 132, or is worth

　　

1#include <stdio.h>2#include <stdlib.h>3#include <string.h>4 #defineMAX (a) (a) > (b)? (a):(B)5 #defineCUTOFF 206 7typedefintPosition;8typedefstructinput9 {Ten     intStart_hour; One     intEnd_hour; A     inteff; - }list; -  theLIST list[ +]; - Long Longdp1[1001]; - Long Longdp2[1001]; -  + voidQuick_sort (Position, Position); - voidSwap (Position, Position); + voidInsertion_sort (Position, Position); A intMedian_of_three (Position, Position, Position); at voidSearch (Const int,Const int,Const int); -  - intMainvoid) - { -     intinterval, R, N, I; -  in      while(~SCANF ("%d%d%d", &n, &interval, &R)) -     { to          for(i =1; I <= interval; i++) +scanf"%d%d%d", &list[i].start_hour, &list[i].end_hour, &List[i].eff); -list[0].start_hour = Int_min; list[0].end_hour =-R; theQuick_sort (1, interval); * Search (N, interval, R); $     }Panax Notoginseng     return 0; - } the  + intMedian_of_three (Position left, Position Middle, Position right) A { the     if(List[left].start_hour >list[middle].start_hour) + Swap (left, middle); -     if(List[left].start_hour >list[right].start_hour) $ Swap (left, right); $     if(List[middle].start_hour >list[right].start_hour) - Swap (middle, right); -Swap (middle, right);//Hide Pivot Element the     returnList[right].start_hour; - }Wuyi  the voidSwap (Position x, Position y) - { WuList[x].start_hour ^=List[y].start_hour; -List[y].start_hour ^=List[x].start_hour; AboutList[x].start_hour ^=List[y].start_hour; $  -List[x].end_hour ^=List[y].end_hour; -List[y].end_hour ^=List[x].end_hour; -List[x].end_hour ^=List[y].end_hour; A  +List[x].eff ^=List[y].eff; theList[y].eff ^=List[x].eff; -List[x].eff ^=List[y].eff; $ } the  the voidInsertion_sort (Position left, Position right) the { the Position I, J; -     inttmp_s, Tmp_e, Tmp_eff; in      for(i = left +1; I <= right; i++) the     { thetmp_s =List[i].start_hour; AboutTmp_e =List[i].end_hour; theTmp_eff =List[i].eff; the          for(j = i; j > left && list[j-1].start_hour > tmp_s; j--) the         { +List[j].start_hour = List[j-1].start_hour; -List[j].end_hour = List[j-1].end_hour; theList[j].eff = List[j-1].eff;Bayi         } theList[j].start_hour =tmp_s; theList[j].end_hour =tmp_e; -List[j].eff =Tmp_eff; -     } the } the  the voidQuick_sort (Position left, Position right) the { -Position mid = (left + right)/2, I, J; the     intpivot; the  the     if(Right-left >CUTOFF)94     { thePivot =Median_of_three (left, Mid, right); thei = left; j =Right ; the          while(1)98         { About              while(List[++i].start_hour <pivot); -              while(List[--j].start_hour >pivot);101             if(I <j)102 Swap (i, j);103             Else  Break;104         } the Swap (I, right);106Quick_sort (left, I-1);107Quick_sort (i +1, right);108     }109     ElseInsertion_sort (left, right); the }111  the voidSearch (Const intNConst intIntervalConst intR)113 { the     intI, J; the     Long LongAns =-1; the     Long Long*now = DP2, *prev = dp1, *tmp =NULL;117 118      for(i =1; I <= interval; i++)119     { -          for(j = i-1; J >=0; j--)121         {122NOW[J] =Prev[j];123             if(List[i].start_hour-list[j].end_hour >=R)124Now[i] = MAX (Now[i], now[j] +List[i].eff); theAns =MAX (ans, now[i]);126         }127TMP = Now; now = prev; Prev =tmp; -     }129printf"%lld\n", ans); the}

Dp:miking time (POJ 3616)