diedai.zip.rar_方程 迭代_解方程

#include<iostream.h> #include<stdlib.h> #define p(i,x) p[(i)*(n+1)+x] char suoming() { cout<<"if use Jacobi diedai,please input j:\n"; cout<<"if use Gauss-Seidel diedai,please input g:\n"; cout<<"if use SOR diedai,please input s:\n"; cout<<"input a char:"; char c; cin>>c; return c; } void huhuan(float *p1,float *p2,int n) { int i; float s; for(i=0;i<n;++i) { s=p1[i];p1[i]=p2[i];p2[i]=s; } } void jdiedai(float *p,float *p1,float *p2,int n) { int i,j; float s; for(i=0;i<n;++i) { s=0; for(j=0;j<n;++j) { if(j==i) continue; s+=p(i,j)*p2[j]; } p1[i]=(p(i,n)-s)/p(i,i); } } void sordiedai(float *p,float *p1,float *p2,int n,float w) { int i,j; float s; for(i=0;i<n;++i) { s=0; if(i>0) for(j=0;j<i;++j) s+=p(i,j)*p1[j]; for(j=i;j<n;++j) s+=p(i,j)*p2[j]; p1[i]=p2[i]+w*(p(i,n)-s)/p(i,i); } } float f(float s,float t) { if(s-t<0) return t-s; else return s-t; } float wuqiongfan(float *p1,float *p2,int n) { int i,j; float s=0,t=0; for(i=0;i<n;++i) { if(i==0) for(j=0;j<n;++j) s+=f(p1[j],p2[j]); for(j=1;j<n;++j) t+=f(p1[j],p2[j]); if(s<t) s=t; t=0; } return s; } void main() { int i,x,n; float *p,*p1,*p2,w,epc,s=10,k=0; char c; cout<<"input the number of equations:"; cin>>n; p=new float[n*(n+1)]; p1=new float[n]; p2=new float[n]; cout<<"input A["<<n<<"*"<<n<<"]:\n"; for(i=0;i<n;++i) for(x=0;x<n;++x) cin>>p(i,x); cout<<"intput b[b1 .... b"<<n<<"]\n"; for(i=0;i<n;++i) cin>>p(i,n); for(i=0;i<n;++i) p2[i]=0; c=suoming(); cout<<"input kong zhi tiao jian:||X(k+1)-X(k)||<?"; cin>>epc; if(c=='s') {cout<<"please input w:"; cin>>w;} if(c=='g') w=1; if(c!='j') while(s>=epc) { k++; sordiedai(p,p1,p2,n,w); s=wuqiongfan(p1,p2,n); if(s>=epc) huhuan(p1,p2,n); } if(c=='j') while(s>=epc) { k++; jdiedai(p,p1,p2,n); s=wuqiongfan(p1,p2,n); if(s>=epc) huhuan(p1,p2,n); } cout<<"No."<<k<<":"<<endl; cout.precision(8); cout.setf(ios::fixed); for(i=0;i<n;++i) cout<<p1[i]<<endl; delete p; delete p1; delete p2; }