bjoj1911 [Apio2010] Sequence Segmentation

1911: [Apio2010] Special Action Team time limit:4 Sec Memory limit:64 MB
submit:4486 solved:2140
[Submit] [Status] [Discuss] Description input Output Sample input4
-1 10-20
2 2 3 4Sample Output9HINT

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Transformation conditions, digging in-depth information, the answer is actually equal tok+1 segment 22 multiplied (multiplication principle YY), unrelated to the order of the cut,ans=σCj * (CI-CJ);; (ans=∑ans=∑ Section i x front I-1 of the paragraph); so UnderK stage to dynamically plan, so that F[i][j] represents the first J number into the maximum score of I segment, then there isF[i] [J]=Max{f[i]1][k ]+c[k]x (C[J]? C[k])}; then use the scrolling array to optimize the slope: AttentionC[i] is likely to be 0, (0 in the equation ), so do not getx, multiply with the cale () function;

1#include <algorithm>2#include <iostream>3#include <iomanip>4#include <cstdlib>5#include <cstring>6#include <cstdio>7#include <vector>8#include <cmath>9#include <queue>Ten#include <stack> One#include <map> A#include <Set> - #definell Long Long - #defineRep (i,a,b) for (register int i=a;i<=b;++i) the #defineRe Register - using namespacestd; - Const intn=100010; -ll dp[2][n],c[n]; + intN,q[n]; - inline ll gi () + { All ret=0;CharCh=GetChar (); at      while(ch<'0'|| Ch>'9') ch=GetChar (); -      while(ch>='0'&&ch<='9') ret=ret*Ten+ch-'0', ch=GetChar (); -     returnret; - } -ll Getnum (intNowintIintBJ) { -     returnDp[!bj][i] + c[i]* (c[now]-c[i]); in } - BOOLCaleintL1,intL2,intL3,intBJ) { toll b1= Dp[!bj][l1]-c[l1]*c[l1],b2=dp[!bj][l2]-C[L2]*C[L2], B3=DP[!BJ][L3]-C[L3]*C[L3];//Bug +     return(B3-B2) * (C[l1]-c[l2]) <= (B2-B1) * (c[l2]-C[l3]); - } the intMain () * { $ Panax NotoginsengN=gi ();intk=gi (); -Rep (I,1, n) c[i]=gi (), c[i]+=c[i-1]; theReintbj=1, Hd,tl; +      for(Reintu=1; u<=k;u++) { Abj=!BJ; theHd=tl=0; q[0]=0; +          for(ReintI=1; i<=n;i++) { -              while(hd+2<=tl&&cale (q[tl-2],q[tl-1],Q[TL],BJ)) q[tl-1]=q[tl--];// $              while(Hd<tl&&getnum (I,Q[HD],BJ) <=getnum (i,q[hd+1],BJ)) hd++; $dp[bj][i]=Getnum (I,Q[HD],BJ); -q[++tl]=i; -         } the     } -printf"%lld", Dp[bj][n]);Wuyi     return 0; the}

bjoj1911 [Apio2010] Sequence Segmentation