return a+b;
}
public int subtraction(int a,int b){
return a-b;
}
public int multiply(int a,int b){
return a*b;
}
public int division(int a,int b){
if(b!=0){
return a/b;
}else{
return -1;
}
}
public int yu(int a,int b){
if(b!=0){
return a%b;
}else{
return -2;
}
}
主函數調用，僅供參考！