#include<iostream.h>

int main()

{

int xuanze;
int rmbi;
int waibi;
int huilv;

cout <<"************************************************\n"
<<"*******①人民币兑换外币**②外币兑换人民币*******\n"
<<"************************************************\n"
<<"*请选择";
cin >>xuanze;
cout <<"************************************************\n";

if(xuanze=1)

cout <<"************************************************\n"
<<"请输入人民币数量:";
cin >>rmbi;
cout <<"************************************************\n"
<<"请输入汇率:";
cin >>huilv;
cout <<"************************************************\n"
<<"可兑换外币:"
<<rmbi*huilv <<"\n"
<<"************************************************\n";

if(xuanze=2)

cout <<"************************************************\n"
<<"请输入外币数量:";
cin >>waibi;
cout <<"************************************************\n"
<<"请输入汇率:";
cin >>huilv;
cout <<"************************************************\n"
<<"可兑换人民币:"
<<waibi/huilv <<"\n"
<<"************************************************\n";

}

楼主的意思是这样哇？

#include<iostream.h>

int main()

{

int xuanze;
int rmbi;
int waibi;
int huilv;

cout <<"************************************************\n"
<<"*******①人民币兑换外币**②外币兑换人民币*******\n"
<<"************************************************\n"
<<"*请选择";
cin >>xuanze;
cout <<"************************************************\n";

if(xuanze==1)
{
cout <<"************************************************\n"
<<"请输入人民币数量:";
cin >>rmbi;
cout <<"************************************************\n"
<<"请输入汇率:";
cin >>huilv;
cout <<"************************************************\n"
<<"可兑换外币:"
<<rmbi*huilv <<"\n"
<<"************************************************\n";
}
if(xuanze==2)
{
cout <<"************************************************\n"
<<"请输入外币数量:";
cin >>waibi;
cout <<"************************************************\n"
<<"请输入汇率:";
cin >>huilv;
cout <<"************************************************\n"
<<"可兑换人民币:"
<<waibi/huilv <<"\n"
<<"************************************************\n";
}

return 0;
}


lz应该多练练基本功