谁能帮我将以下简单的C程序改成下拉菜单式的!

#include <stdio.h>#include <stdlib.h>#include <math.h>#include <windows.h>#define pi 3.14159 double volum3(double s,double h) {return 1.0/3*s*h;} double area2(double a,double b) { double s1,s2;s1=2.0*pi*a*b;s2=pi*a*a;return s1+s2;} double area1 (double a,double b) {double s1,s2;s1=pi*a*sqrt(a*a+b*b);s2=pi*a*a;return s1+s2;} double volume1 (double a,double b) {double v;v=pi*a*a*b*1.0/3;return v;} main() {int t,p,i=0;double s1,s2,s3,v1,v2,v3,r1,h1,r2,h2,h3;loop2: printf("please press the code(two thousands and nine):");scanf("%d",&p);if(p==2009) { getchar();system("CLS");for(i=0;i <1;i++) printf("\n");printf("\n");printf("\n");printf("\n");printf("welcome to you\n\n");Sleep(3000);system("cls");loop: printf("==================================\n");printf("|1.the Calculation of cones |\n");printf("==================================\n");printf("|2.the Calculation of cylinders|\n");printf("==================================\n");printf("|3.the Calculation of pyramids|\n");printf("==================================\n");printf("|0. exit the program |\n");printf("==================================\n");scanf("%d",&t);system("cls");switch(t) {case 1:printf("please output of the bottom radius of cone\n");scanf("%lf",&r1);if(r1 <=0) {printf("error");goto loop;} printf("please output of the high of cone\n");scanf("%lf",&h1);if(h1 <=0) {printf("error");goto loop;} v1=volume1 (r1,h1);s1=area1(r1,h1);printf("the volum is %f\n the area is%f\n",v1,s1);break;case 2:printf("please output of the bottom radius of the cylinder\n");scanf("%lf",&r2);if(r2 <=0) {printf("error");goto loop;} printf("please output of the high of cylinder\n");scanf("%lf",&h2);if(h2 <=0) {printf("error");goto loop;} v2=3*volume1(r2,h2);s2=area2(r2,h2);printf("the volum is %lf\n the area is%lf\n",v2,s2);break;case 3:printf("please output the footprint of pyramid\n");scanf("%lf",&s3);printf("please output of the high of pyramid\n");scanf("%lf",&h3);if(s3 <=0) {printf("error");goto loop;} v3=volum3(s3,h3);printf("the volum is %lf\n ",v3);break;case 0: for(i=0;i <1;i++) printf("\n"收起