UVA 12905 Volume of Revolution

Test instructions: The volume is approximated by the cone area, then the relative error of the approximate value and the true value is calculated.

Calculus plus Math.

Volumetric calculation formula for flat-head vertebral table:

V = 1/3*h* (s1+s2*sqrt (S1*S2)

A faster way to calculate polynomial values, to be proud of ye, the algorithm is for (int i = 0; I >= i--) ans + = ans*x+p[i], one times faster than I wrote this

#include <cstdio>#include<cmath>#include<cstring>Const DoublePI = Atan (1)*4;intpoly[8],q[ -],n;inlineDoubleCALR (Doublex) {    DoubleAns = poly[0];  for(inti =1; I <= N; i++) {ans+ = poly[i]*Pow (x,i); }    returnans;} InlineDoubleCalint (intx) {    DoubleAns =0;  for(inti =0, Sz = n<<1; I <= sz; i++) {ans+ = Q[i]*pow (x,i+1)/(i+1); }    returnans;} InlineDoubleCalV (intAintb) {memset (Q,0,sizeof(Q));  for(inti =0; I <= N; i++){         for(intj =0; J <= N; J + +) Q[i+J] + = poly[i]*Poly[j]; }    return(Calint (b)-calint (a)) *Pi;} InlineDoubleCalS (DoubleRDoubleThetaintslices) {    returnR*sin (theta)/2*r*slices;}intMain () {intT; scanf ("%d",&T); intCAS =0;  while(t--) {memset (poly,0,sizeof(poly)); scanf ("%d",&N);  for(inti = n; I >=0; i--) scanf ("%d", poly+i); intb; scanf ("%d%d",&a,&b); intslices,stacks; scanf ("%d%d",&slices,&stacks); DoubleDX = (b-a) *1.0/stacks, Dtheta =2*pi/slices; DoubleR1 = CALR (a), S1 =CalS (r1,dtheta,slices); Doublex = A +DX; DoubleApe =0;  for(inti =0; I < stacks; i++){            DoubleR2 =calr (x); DoubleS2 =CalS (r2,dtheta,slices); DoubleDS = dx/3* (S1+s2+sqrt (s1*S2)); Ape+=DS; X+=DX; R1= R2; S1 =S2; }        Doublevol =CalV (A, b); printf ("Case %d:%.4lf\n", ++cas,fabs (Ape-vol)/vol* -); }    return 0;}

UVA 12905 Volume of Revolution