猜数字小游戏升级

#include <iostream>
#include <ctime>
#include <unistd.h>
#include <cstdio>
#include <cstdlib>
using namespace std;

inline int read()
{
    int s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}

inline void write(int x)
{
     if(x<0) putchar('-'),x=-x;
     if(x>9) write(x/10);
     putchar(x%10+'0');
}

int main()
{
	char ch = 'N';
	int score = 0;
	do
	{ 
	srand(time(0));
	sleep(1);
	int x = rand();
	srand(time(0)*time(0)*time(0)+83475*time(0)+985);
	sleep(1);
	int y = rand();
	srand(time(0)*time(0)+4758945*time(0)+1);
		sleep(1);
	int z = rand() % 4;
	if(z == 0)
	{
		printf("%d+%d=%c\n", x, y, '?');
		int a;
		cin>>a;
		if(a==x+y)
		{
			printf("√\n");
			score ++;
		}
		else
		{
			printf("×\n");
		}
	}
	else if(z == 1)
	{
		printf("%d-%d=%c\n", x, y, '?');
		int a;
		cin>>a;
		if(a==x-y)
		{
			printf("√\n");
			score ++;
		}
		else
		{
			printf("×\n");
		}
	}
	else if(x == 2)
	{
		printf("%d*%d=%c\n", x, y, '?');
		int a;
		cin>>a;
		if(a==x*y)
		{
			printf("√\n");
			score ++;
		}
		else
		{
			printf("×\n");
		}
	}
	else
	{
		printf("%d/%d=%c\n", x, y, '?');
		int a;
		cin>>a;
		if(a==x/y)
		{
			printf("√\n");
			score ++;
		}
		else
		{
			printf("×\n");
		}
	}
	printf("score=%d\n", score);
	sleep(2);
	system("cls");
	}while(getchar() != EOF); 
	printf("得分：！score=%d\n", score);
	return 0;
}