问题描述
#include"stdlib.h"#include"math.h"voidrkt2(t,h,y,n,eps,f)void(*f)();intn;doublet,h,eps,y[];{intm,i,j,k;doublehh,p,dt,x,tt,q,a[4],*g,*b,*c,*d,*e;g=malloc(n*sizeof(double));b=malloc(n*sizeof(double));c=malloc(n*sizeof(double));d=malloc(n*sizeof(double));e=malloc(n*sizeof(double));hh=h;m=1;p=1.0+eps;x=t;for(i=0;i<=n-1;i++)c[i]=y[i];while(p>=eps){a[0]=hh/2.0;a[1]=a[0];a[2]=hh;a[3]=hh;for(i=0;i<=n-1;i++){g[i]=y[i];y[i]=c[i];}dt=h/m;t=x;for(j=0;j<=m-1;j++){(*f)(t,y,n,d);for(i=0;i<=n-1;i++){b[i]=y[i];e[i]=y[i];}for(k=0;k<=2;k++){for(i=0;i<=n-1;i++){y[i]=e[i]+a[k]*d[i];b[i]=b[i]+a[k+1]*d[i]/3.0;}tt=t+a[k];(*f)(tt,y,n,d);}for(i=0;i<=n-1;i++)y[i]=b[i]+hh*d[i]/6.0;t=t+dt;}p=0.0;for(i=0;i<=n-1;i++){q=fabs(y[i]-g[i]);if(q>p)p=q;}hh=hh/2.0;m=m+m;}free(g);free(b);free(c);free(d);free(e);return;}
解决方案
解决方案二：
顶:-)