c四則運算自動生成程序

#include<bits/stdc++.h>
#include<windows.h>
using namespace std;
int sum = 0;
int rr = 0;
int mulu()
{
	puts("請選擇難度：\n");
	puts("1.10以內\n") ;
	puts("2.100以內\n");
	puts("3.1000以內\n");
	int h;
	scanf("%d",&h);int flag = 1;
	while(flag)
	{
		switch(h)
		{
			case 1:flag = 0;return 10;
				case 2:flag = 0;return 100;
					case 3:flag = 0;return 1000;
						default:printf("請重新輸入\n");flag = 1;break;
		}	
	}
}
void ti()
{
	puts("請輸入題量："); 
	scanf("%d",&sum);
	puts("ok\n");
}
void fushu()
{
	ti();
	int flag = mulu();
	for(int  i = rr;i < rr + sum;++i)
	{
		int g1 = -(rand()%flag);
		int g2 = -(rand()%flag);	
		int h = rand()%4;int ans;double hh;
		switch(h)
		{
			case 0:printf("%d+%d= ",g1,g2);puts("請輸出答案：");scanf("%d",&ans);
			if(ans==g1+g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1+g2);	
			}
			break;
			case 1:printf("%d-%d= ",g1,g2);puts("請輸出答案：");scanf("%d",&ans);
			if(ans==g1-g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1-g2);	
			}
			break;
			case 2:printf("%d*%d= ",g1,g2);puts("請輸出答案：");scanf("%d",&ans);
			if(ans==g1*g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1*g2);	
			}
			break;
			case 3:printf("%d/%d= ",g1,g2);puts("請輸出答案：");scanf("%lf",&hh);
			if(hh==g1/g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1/g2);	
			}
			break;
			default:break;
		}
	}
}
void xiaoshu()
{
	ti();
	int flag = mulu();
	for(int  i = rr;i < rr + sum;++i)
	{
		int h5 = rand()%flag+1;
		int h6 = rand()%flag;
		float h3 = rand()%100;
		float h4 = rand()%100;
		float g1 = 	h5+h3/100.0;
		float g2 = 	h6+h4/100.0;
		int h = rand()%4;float ans;float hh;
		switch(h)
		{
			case 0:printf("%f+%f= ",g1,g2);puts("請輸出答案：");scanf("%f",&ans);
			if(ans==g1+g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%f\n",g1+g2);	
			}
			break;
			case 1:printf("%f-%f= ",g1,g2);puts("請輸出答案：");scanf("%f",&ans);
			if(ans==g1-g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%f\n",g1-g2);	
			}
			break;
			case 2:printf("%f*%f= ",g1,g2);puts("請輸出答案：");scanf("%f",&ans);
			if(ans==g1*g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%f\n",g1*g2);	
			}
			break;
			case 3:printf("%f/%f= ",g1,g2);puts("請輸出答案：");scanf("%f",&hh);
			if(hh==g1/g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%f\n",g1/g2);	
			}
			break;
			default:break;
		}
	}
}
string s ; 
int cnt = 0 ; 
int term() ;
int factor() ;
int expression(){
	int t ;
	t = term() ; 
	while(1){
		if(s[cnt] == '+' ){ // 判斷爲+ 繼續 
			cnt++ ; // 下一位 
			t = t + term() ; // 進去term計算數值 
		}else if(s[cnt] == '-'){ 
			cnt++ ;
			t = t - term() ; 
		}else break ; 
	}
	return t ; 
}
int term() {
	int f;
	f = factor(); // 進入 factor 函數 
	while(1){	
		if(s[cnt]=='*') { // 判斷爲乘除則進入factor計算數值 
			cnt++;
			f = f * factor();
		} else if(s[cnt]=='/') {
			cnt++;
			f = f / factor();
		} else break;
	}
	return f;
}
int factor() {
	int f;
	if(s[cnt]=='(') { // 如果判斷爲括號則回到 expression 中相當從新開始 
		cnt++ ; 
		f = expression();
		if(s[cnt]==')') cnt++;
		return f;
	}
	f=0;
	while('0'<=s[cnt] && s[cnt]<='9') { //如果是數字就計算這個數字是多少返回到上一個函數 
		f=f*10+(s[cnt]-'0');
		cnt++;
	}
	return f;
}
void daikuohao()
{
	ti();
	int flag = mulu();
	int g1 = rand()%flag;
	int g2 = rand()%flag;
	int g3 = rand()%flag;
	int g4 = rand()%flag;
	s+="(";
	stringstream aa;
	aa << g1;
	string h1;
	aa >> h1;
	s += h1;
	int hh = rand()%7;
	
	switch(hh)
	{
		case 0:s+="+";break;
		case 1:s+="-";break;
		case 2:s+="*";break;
		case 3:break;
		case 4:s+=")+(";break;
		case 5:s+=")*(";break;
		case 6:s+=")-(";break;
	}
	stringstream aa1;
	aa1 << g2;
	aa1 >> h1;
	s += h1;
	hh = rand()%4;
	switch(hh)
	{
		case 0:s+="+";break;
		case 1:s+="-";break;
		case 2:s+="*";break;
		case 3:break; 	
	}
	stringstream aa2;
	aa2 << g3;
	aa2 >> h1;
	s += h1;
	hh = rand()%4;
	switch(hh)
	{
		case 0:s+="+";break;
		case 1:s+="-";break;
		case 2:s+="*";break;
		case 3:break; 	
	}
	stringstream aa3;
	aa3 << g4;
	aa3 >> h1;
	s += h1;
	s += ")";
	cout<<s<<" ";
	cout<<"請輸出答案:";
	int ans;
	cin>>ans;
	int aaa = expression();
	if(ans == aaa)
	{
		printf("答案正確\n");
	}
	else{
		printf("錯誤，正確答案是：");
		cout<<aaa<<endl; 
	}
	Sleep(1000);
}
void putong()
{
	ti();
	int flag = mulu();
	for(int  i = rr;i < rr + sum;++i)
	{
		int g1 = rand()%flag;
		int g2 = rand()%flag;	
		int h = rand()%4;int ans;double hh;
		switch(h)
		{
			case 0:printf("%d+%d= ",g1,g2);puts("請輸出答案：");scanf("%d",&ans);
			if(ans==g1+g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1+g2);	
			}
			break;
			case 1:printf("%d-%d= ",g1,g2);puts("請輸出答案：");scanf("%d",&ans);
			if(ans==g1-g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1-g2);	
			}
			break;
			case 2:printf("%d*%d= ",g1,g2);puts("請輸出答案：");scanf("%d",&ans);
			if(ans==g1*g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1*g2);	
			}
			break;
			case 3:printf("%d/%d= ",g1,g2);puts("請輸出答案：");scanf("%lf",&hh);
			if(hh==g1/g2)
			{
				printf("答案正確\n");	
			}
			else{
				printf("錯誤\n");
				printf("正確答案是%d\n",g1/g2);	
			}
			break;
			default:break;
		}
	}
}
int main()
{
	//freopen("1.txt","r",stdin);
    //freopen("2.txt","w",stdout);
    system("color A"); 
	while(1)
	{
		system("cls");
		int n;
		puts("         四則運算自測軟件\n");
		puts("請選擇選項：\n");
		puts("1.負數\n");
		puts("2.小數\n");
		puts("3.帶括號\n");
		puts("4.普通\n");
		puts("5.退出\n");
		scanf("%d",&n); 
		switch(n)
		{
			case 1:fushu();break;
			case 2:xiaoshu();break;
			case 3:daikuohao();break;
			case 4:putong();break;
			default:return 0; 
		} 
	}
	
	return 0;
}