POJ 1661-help JIMMY-DP

A DP simulation problem.

Give n boards and an initial coordinate xy, starting from X, Y, and jumping down, with a maximum hop-down distance.

Both walking and jumping on the board are time consuming. Calculates the shortest time to reach the ground.

Sort the boards by height

Dp[i][0] Indicates the time to reach the left edge of Block I, dp[i][1] indicates the time to reach the right edge.

Then dp[i][0] = min (Dp[k][0]+f (), Dp[k][1]+f ()) k is less than I can jump to I on the board. F () indicates the time required from the left/right edge of K to the left edge of I.

Dp[i][1] = min (Dp[k][0]+f (), dp[k][1]+f ())

Pay attention to determine whether K can jump to I more trouble, K at the end of the coordinates in I, and K has not jumped the board, because one side of the board may only jump to a single board, or the ground.

Finally, the minimum value of the DP value at one end of the board that can jump directly to the ground is maintained.

1#include <cstdio>2#include <cstring>3#include <algorithm>4 5 using namespacestd;6 7 Const intMAXN = ++Ten;8 Const intINF =0x3f3f3f3f;9 Ten structtable{ One     intL,r; A     intheight; -     BOOL operator< (ConstTable &AMP;RHS)Const -     { the         returnHeight >Rhs.height; -     } - }TABLE[MAXN]; -  + intN,x0,y0,max; - intT; + intdp[maxn][2]; A intvis[maxn],next[maxn][2]; at  - BOOLCheckintIintj) - { -     if(Table[j].height-table[i].height <= Max && table[j].height! =table[i].height) -         return true; -     Else in         return false; - } to  + intMain () - { thescanf"%d",&T); *      while(t--) $     {Panax Notoginsengscanf"%d%d%d%d",&n,&x0,&y0,&Max); -          for(intI=1; i<=n;i++) the         { +scanf"%d%d%d",&table[i].l,&table[i].r,&table[i].height); A             if(Table[i].l >TABLE[I].R) the swap (TABLE[I].L,TABLE[I].R); +         } -  $Sort (table+1, table+1+N); $memset (Vis,0,sizeofvis); -Memset (Next,0,sizeofnext); -  the          for(intI=0; i<=n;i++) -dp[i][0] = dp[i][1] =INF;Wuyi         intAns =INF; the         intFlag =0; -  Wu          for(intI=1; i<=n;i++) -         { About             if(Y0-table[i].height > Max) Break; $             if(X0 >= table[i].l && X0 <=TABLE[I].R) -             { -dp[i][0] = y0-table[i].height + X0-TABLE[I].L; -dp[i][1] = y0-table[i].height + TABLE[I].R-X0; AVis[i] =true; +Flag =1; the                  Break; -             } $         } the  the         if(!flag) the         { theprintf"%d\n", Y0); -             Continue; in         } the  the          for(intI=1; i<=n;i++) About         { the              for(intj=i-1; j>=1; j--)if(Check (I,J) &&Vis[j]) the             { the                 if(!next[j][0] && table[j].l <= table[i].r && table[j].l >=table[i].l) +                 { -next[j][0] =true; theVis[i] =true;Bayidp[i][0] = min (dp[j][0]+table[j].height-table[i].height+table[j].l-table[i].l,dp[i][0]); thedp[i][1] = min (dp[j][0]+table[j].height-table[i].height+table[i].r-table[j].l,dp[i][1]); the                 } -                 if(!next[j][1] && table[j].r >= table[i].l && TABLE[J].R <=TABLE[I].R) -                 { thenext[j][1] =true; theVis[i] =true; thedp[i][0] = min (dp[j][1]+table[j].height-table[i].height+table[j].r-table[i].l,dp[i][0]); thedp[i][1] = min (dp[j][1]+table[j].height-table[i].height+table[i].r-table[j].r,dp[i][1]); -                 } the             } the             //printf ("l:%d r:%d \ n", dp[i][0],dp[i][1]); the         }94  the          for(inti=n;i>=1; i--)if(Vis[i] && table[i].height <=Max) the         { the             if(!next[i][0]) ans = min (ans,dp[i][0]+table[i].height);98             if(!next[i][1]) ans = min (ans,dp[i][1]+table[i].height); About  -             //printf ("h:%d l:%d r:%d [%d,%d] \ n", table[i].height,dp[i][0],dp[i][1],next[i][0],next[i][1]);101         }102printf"%d\n", ans);103     }104}

Recently did a lot of DP water problems, but do not want to upload, too much water.

POJ 1661-help JIMMY-DP