bzoj3675: [Apio2014] Sequence Segmentation

Leave pit

Why the slope optimization of other people's home is not the same as mine!

Why does the slope have to become positive ...

Why do you have to push the equation?

Why can't you just do it?

Why don't you get rid of 0 and go to WA?

Why does the cross-product go to 0?

WoC.

1#include <cstdio>2#include <cstring>3#include <cstdlib>4#include <algorithm>5#include <iostream>6 7 using namespacestd;8 9 voidSetio (Const string&s) {TenFreopen ((S +". in"). C_STR (),"R", stdin); OneFreopen ((S +". out"). C_STR (),"W", stdout); A } -Template<typename q> Q Read (q&x) { -     Static Charc, F; the      for(f =0; c = GetChar (),!isdigit (c); )if(c = ='-') F =1; -      for(x =0; IsDigit (c); c = GetChar ()) x = x *Ten+ C-'0'; -     if(f) x =-x; -     returnx; + } -Template<typename q>Q Read () { +     StaticQ x; Read (x);returnx; A } at  -typedefLong LongLL; - Const intN =100000+Ten; -  -LL Sqr (Constll&x) { -     returnX *x; in } -  to LL F[n], g[n], sum[n]; + intQ[n]; -  theLL Up (inti) { *     returnG[i]-Sqr (Sum[i]); $ }Panax Notoginseng  -LL Up (intIintj) { the     returnUp (j)-Up (i); + } A  theLL Down (intIintj) {//>= 0 +     returnSUM[J]-Sum[i]; - } $  $ DoubleSlopeintIintj) { -     returnUp (I, j)/(Double) Down (i, j); - } the intN; - Wuyi structNode { the LL x, y; - Node () {} WuNode (Constll& x,Constll&y): x (x), Y (y) {} -Nodeoperator- (Constnode& RHS)Const { About         returnNode (x-rhs.x, Y-rhs.y); $     } - }p[n]; -  -LL Cross (Constnode& A,Constnode&b) { A     returna.x * b.y-b.x *a.y; + } the  - voiddpintSt) { $     intL =0, R =0; theq[r++] =St; the      for(inti = st +1; I <= N; i++) { the //while (L + 1 < R &&-sum[i] < slope (Q[l], q[l + 1])) l++; the //while (L + 1 < R &&-sum[i] * Down (q[l], q[l + 1]) < up (Q[l], q[l + 1])) l++; -          while(L +1< R && Cross (Node (1,-sum[i]), P[l +1]-p[l]) >=0) l++; in         intj =Q[l]; theF[i] = G[j] + sum[j] * (sum[i)-sum[j]); the //While (L + 1 < R && Slope (q[r-2], q[r-1]) < slope (Q[r-2], i)) r--; About //While (L + 1 < R && up (Q[r-2], q[r-1]) * Down (q[r-2], i) < up (Q[r-2], i) * Down (q[r-2], Q[R-1]) r--; the Node u (sum[i], up (i)); the          while(L +1< R && Cross (P[r-1]-P[r-2], U-p[r-2]) >=0) r--; theQ[r] = i, p[r++] =u; +     } -      for(inti = st +1; I <= N; i++) G[i] =F[i]; the }Bayi  the intMain () { the #ifdef DEBUG -Freopen ("In.txt","R", stdin); -Freopen ("OUT.txt","W", stdout); the #endif the      the read (n); the     intK = read<int>(); -      the      for(inti =1; I <= N; i++) { the         intx = read<int>(); the         if(!x) I--, n--;94         ElseSum[i] = sum[i-1] +x; the //Sum[i] = sum[i-1] + read<int> (); the     } the     98      for(inti =1; I <= K; i++) DP (i); About      -printf"%lld\n", G[n]);101     102     return 0;103}

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bzoj3675: [Apio2014] Sequence Segmentation