Function returning string

Can any one correct the following code and explain...
The function decode is returning a string and i want that local string to be stored in another string in main which calls that function.

#include<iostream.h> #include<conio.h> #include<string.h> void decode(char q[]); int main() { //p refers to orignal string and q refers to quoted string char a,b,c,d,e,f,g,h,i; char p[]="011100011"; cout<<p; cout<<endl; a=(p[0]+p[1]-'0'); b=((p[0]+p[1]-'0'+p[2])-'0'); c=((p[1]+p[2]-'0'+p[3])-'0'); d=((p[2]+p[3]-'0'+p[4])-'0'); e=((p[3]+p[4]-'0'+p[5])-'0'); f=((p[4]+p[5]-'0'+p[6])-'0'); g=((p[5]+p[6]-'0'+p[7])-'0'); h=((p[6]+p[7]-'0'+p[8])-'0'); i=(p[7]+p[8]-'0'); char q[9]={a,b,c,d,e,f,g,h,i}; char sum[]=decode(q); cout<<sum; } return decode(char q[]) { char ap,bp,cp,dp,ep,fp,gp,hp,ip; ap=0; bp=q[1]-ap; cp=q[2]-ap-bp; dp=q[3]-bp-cp; ep=q[4]-cp-dp; fp=q[5]-dp-ep; gp=q[6]-ep-fp; hp=q[7]-fp-gp; ip=q[8]-gp-hp; char string1[]={ap,bp,cp,dp,ep,fp,gp,hp,ip}; return string1; }