Program Bisection dan Secant C++

Program Bisection dan Secant

#include <iostream.h>
#include <stdlib.h>
#include <coni0.h>
#include <mah.h>

//variabel global
float galat;
int iterasi,i;
//variabel secant
float x0,x1;
float x2,xi;
float fx0,fx1;
int fnol(float x0);
int fsatu(float x1);
//variabel bisection
float xl,xu,xm0;
float fxl,fxu;
float fxm,xm;
float h1,h2;
int fungsi(float xm);
int fungsi2(float xl);
int fungsi3(float xu);
int step4(float xm,float xm0);
//fungsi yg dipakai


void secant();
void bisection();

void main(){
 int pilih;
 char lagi='y';
 while(lagi=='y'||lagi=='Y'){
 cout<<"---------persamaan linear------\n";
 cout<<" 1.metode bisection\n";
 cout<<" 2.metode secant\n";
 cout<<" 0.keluar program\n";
 cout<<"masukan pilihan (0-2): ";cin>>pilih;
 if(pilih>=0&&pilih<3){
 switch(pilih){
   case 0:exit(1);break;
   case 1:bisection();break;
    case 2:secant();break;
    }
   cout<<"\nmau coba lagi (y/t)??";cin>>lagi;
  }
   else{cout<<"\nanda salah memasukan pilihan,silahkan coba lagi!!\n\n";}
 }
 system("pause");
}

void bisection(){
cout<<"persamaan:f(x)=x^4-2.709x^3+0.665x^2-2.0012*10^-5\n";
//masukan konstanta
cout<<"masukan nilai awal(xl): ";cin>>xl;
cout<<"masukan nilai awal(xu): ";cin>>xu;
cout<<"masukan banyaknya iterasi=";cin>>iterasi;
//hitungan untuk xm 0
xm0=(xl+xu)/2;
//lakukan looping iterasi
 for(i=1;i<=iterasi;i++){
 cout<<"\n*iterasi"<<i<<"\n";
   cout<<"step1:\n"<<xl<<"----------->"<<xu<<"\n";
   xm=(xl+xu)/2;
   cout<<"step2(akar):\n"<<"("<<xl<<"+"<<xu<<")"<<"/2="<<xm<<"\n";
 fungsi(xm);
   fungsi2(xl);
   fungsi3(xu);
   h1=fxl*fxm;
   h2=fxm*fxu;
   cout<<"step3:\n";
   cout<<fxl<<"*"<<fxm<<"="<<h1<<"\n";
   cout<<fxm<<"*"<<fxu<<"="<<h2<<"\n";
  if(h1>0||h2<0){
  xl=xm;
      cout<<"jadi xl--->xm="<<xl;
      cout<<"\ndan xu tetap="<<xu<<"\n";
          if(i>=2){
       step4(xm,xm0);}
         else if(i==1){
         cout<<"iterasi 1 belum bisa menghitung galat\n";
         }
  }
  else if(h1<0||h2>0){
  xu=xm;
      cout<<"jadi xl tetap="<<xl;
      cout<<"\ndan xu--->xm="<<xu<<"\n";
         if(i>=2){
       step4(xm,xm0);}
         else if(i==1){
         cout<<"iterasi 1 belum bisa menghitung galat\n";}
  }
      else{
      iterasi=iterasi-(iterasi-1);
      cout<<"\niterasi gagal, tidak bisa menghitung galat\n";
      }
      xm0=xm;
 }
}
int fungsi(float xm){
fxm=pow(xm,4)-2.709*pow(xm,3)+0.665*pow(xm,2)-2.0012*pow(10,-5);
return xm;
}
int fungsi2(float xl){
fxl=pow(xl,4)-2.709*pow(xl,3)+0.665*pow(xl,2)-2.0012*pow(10,-5);
return xl;
}
int fungsi3(float xu){
fxu=pow(xu,4)-2.709*pow(xu,3)+0.665*pow(xu,2)-2.0012*pow(10,-5);
return xu;
}
int step4(float xm,float xm0){
galat=((xm-xm0)/xm)*100;
cout<<"step4(galat):\n";
cout<<"("<<xm<<"-"<<xm0<<")*100="<<galat<<"\n";
return xm0;
 }

void secant(){
 cout<<"Persamaan:f(x)=2x^3-2.663x^2+4.009*10^-5\n";
 cout<<"masukan nilai awal untuk(x0): ";cin>>x0;
 cout<<"masukan nilai awal untuk(x1): ";cin>>x1;
 cout<<"masukan banyaknya iterasi=";cin>>iterasi;

  for(i=1;i<=iterasi;i++){
   cout<<"\n*iterasi"<<i<<"\n";
   cout<<"step1:\n";
   fnol(x0);
   fsatu(x1);
   x2=x0-(fx0*(x0-x1))/(fx0-fx1);
   cout<<x0<<"-("<<fx0<<"*("<<x0<<"-"<<x1<<"))/("<<fx0<<"-"<<fx1<<")";
   cout<<"\n="<<x2<<"\n";
 
   cout<<"step2(galat):\n";
   galat=((x2-x1)/x2)*100;
   cout<<"(("<<x2<<"-"<<x1<<")/"<<x2<<")*100="<<galat<<"\n";
   x0=x1;
   x1=x2;

   }
}
 int fnol(float x0){ //fungsi untuk fnol
 fx0=2*pow(x0,3)-2.663*pow(x0,2)+4.009*pow(10,-5);
 return fx0;
 }
 int fsatu(float x1){ //fungsi untuk fsatu
 fx1=2*pow(x1,3)-2.663*pow(x1,2)+4.009*pow(10,-5);
 return fx1;
 }

silahkan copas dan edit sendiri... :D