function getNumber(st,def) {var tempo=0;tempo=parseFloat(prompt(st,def)+" ");if (isNaN(tempo)) {tempo=0};return(tempo);};
function solve() {
var n=3;n=getNumber("Please Enter Degree of Polynomial",3);n=Math.floor(n);if (n<1) {n=1};
var r=new Array(n);
var i=new Array(n);
var a=0;
for (a=n;a>0;a--) {r[a]=getNumber("Enter real coeff of x^"+a,1);i[a]=getNumber("Enter imag coeff of x^"+a,0);};
r[0]=getNumber("Enter real constant (RHS=0)",9);i[0]=getNumber("Enter imag constant",0);
c="Solving: ";for (a=n;a>0;a--) {c+="("+r[a];if (i[a]>=0) {c+=" + "};
c+=i[a]+"i)"+"x^"+a+"+";};c+="("+r[0];if (i[0]>=0) {c+=" + "};c+=i[0]+"i)=0";alert(c);
var x=1;var y=10;var accuracy=0.001;//if no convergence, try different values
var flag=false;var tries=0;var a=0;var q=0;
var x1=1;var y1=1;var c=" ";var u=0;var q=0;
var s=0;var t=0;var s1=0;var t1=0;
while ((tries<100) && (n>0)) {
x1=1; y1=1;tries=0;
while ((tries<100) && (Math.abs(x1)+Math.abs(y1)>accuracy)) {

//polynomial evaluation
s=0;t=0;
for (a=n;a>0;a--) {s+=r[a];t+=i[a];u=x*s-y*t;
 t=y*s+t*x;s=u;
 };s+=r[0];t+=i[0];
s1=0;t1=0;a=n;tries++;

//calculate rate of change
while (a>1) {s1+=r[a]*a;t1+=i[a]*a;u=x*s1-y*t1;
 t1=y*s1+t1*x;s1=u;a--;
 };s1+=r[1];t1+=i[1];
q=s1*s1+t1*t1;if (Math.abs(q)<0.000001) {q=0.000001};
x1=(s*s1+t*t1)/q;y1=(-s*t1+t*s1)/q;
x-=x1;y-=y1;};

// division
if (tries<100) {for (a=n-1;a>0;a--) {r[a]+=x*r[a+1]-y*i[a+1];
i[a]+=y*r[a+1]+x*i[a+1];};for (a=0;a<n;a++) {r[a]=r[a+1];
i[a]=i[a+1];};n--;flag=true;

x=(Math.round(1000*x))/1000;
y=(Math.round(1000*y))/1000;
c="Solution: "+x+" ";if (y>=0) {c+="+ "};c+=y+" i ";
alert(c);};else {c="Could not find the "+n;
if (flag) {c+=" remaining "};alert(c+' roots.');};};
alert('End of Program.');
}