有没有人帮我看看要怎么改呜呜呜#include <iostream>using namespace std ; int main ( ){ int add ( int x , int y ) ; float a , b,c; c = minus( a , b ) cout <<"a - b = " << c << endl; return 0 ;} int add ( int x , int y ) ; { z = y - x ; return (z);}