C语言再学习-002-+-*/＞＜……

#include <stdio.h>
main()
{
		int x,y,m;
		printf("Please input x and y\n");
		scanf("%d%d",&x,&y);
		m=x*y;
		printf("%d * %d = %d\n",x,y,m);
}

#include <stdio.h>
main()
{
	float x,y,c;
	printf("Please input x and y:\n");
	scanf("%f%f",&x,&y);
	c=x>y?x:y;
	printf("MAX of (%f,%f) is %f",x,y,c);
}

#include <stdio.h>
main()
{
	char ch,nch;	
	int count;	
	int k;	

	printf("Please input a string with a # in the end.\n");
	scanf("%c",&ch);	
	while(ch != '#')	
	{
		if(ch >= '0' && ch <= '9')
		{
			count = ch-'0'+1;	
			scanf("%c",&nch);	
			for(k=0;k<count;k++)	
				printf("%c",nch);
		}
		else
			printf("%c",ch);	
		printf(" ");			
		scanf("%c",&ch);		
	}
	printf("#\n");			
}

#include <stdio.h>
void main()
{
    printf("The bytes of the variables are:\n");
    printf("int:%d bytes\n",sizeof(int));

    printf("char:%d byte\n",sizeof(char));

    printf("short:%d bytes\n",sizeof(short));

    printf("long:%d bytes\n",sizeof(long));

    printf("float:%d bytes\n",sizeof(float));

    printf("double:%d bytes\n",sizeof(double));

    printf("long double:%d bytes\n",sizeof(long double));
    getchar();

}

#include <stdio.h>
main()
{
	int a=5,b,c,i=10;
	b=a++;
	c=++b;

	printf("a = %d, b = %d, c = %d\n",a,b,c);
	printf("i,i++,i++ = %d,%d,%d\n",i,i++,i++);
	printf("%d\n",++i);
	printf("%d\n",--i);
	printf("%d\n",i++);
	printf("%d\n",i--);
	printf("%d\n",-i++);
	printf("%d\n",-i--);
	getchar();
}

#include <stdio.h>
main()
{
	int i,j,n;
	long sum=0,temp=0;

	printf("Please input a number to n:\n");
	scanf("%d",&n);
	if(n<1)
	{
		printf("The n must no less than 1!\n");
		return;
	}

	for(i=1;i<=n;i++)
	{
		temp=0;
		for(j=1;j<=i;j++)
			temp+=j;
		sum+=temp;
	}
	printf("The sum of the sequence(%d) is %d\n",n,sum);
	getchar();
	getchar();
}

#include <stdio.h>
#include <conio.h>
void main(void)
{
	int i,j,x,y;
	clrscr();
	printf("\n\n multiplication table \n\n");
	x=9;
	y=5;
	for(i=1;i<=9;i++)
	{
		gotoxy(x,y);
		printf("%2d ",i);
		x+=3;
	}
	x=7;
	y=6;
	for(i=1;i<=9;i++)
	{
		gotoxy(x,y);
		printf("%2d ",i);
		y++;
	}
	x=9;
	y= 6;
	for(i=1;i<=9;i++)
	{
		for(j=1;j<=9;j++)
		{
			gotoxy(x,y);
			printf("%2d ",i*j);
			y++;
		}
		y-=9;
		x+=3;
	}
	printf("\n\n");
}

#include <stdio.h>
#include <conio.h>
void main()
{
	int Password=0,Number=0,price=58,i=0;
	clrscr();
	printf("\n====This is a Number Guess Game!====\n");
	while( Password != 1234 )
	{
		if( i >= 3 )
			return;
		i++;
		puts("Please input Password: ");
		scanf("%d",&Password);
	}

	i=0;
	while( Number!=price )
	{
		do{
			puts("Please input a number between 1 and 100: ");
			scanf("%d",&Number);
			printf("Your input number is %d\n",Number);
		}while( !(Number>=1 && Number<=100) );
		if( Number >= 90 )
		{
			printf("Too Bigger! Press any key to try again!\n");
		}
		else if( Number >= 70 && Number < 90 )
		{
			printf("Bigger!\n");
		}
		else if( Number >= 1 && Number <= 30 )
		{
			printf("Too Small! Press any key to try again!\n");
		}
		else if( Number > 30 && Number <= 50 )
		{
			printf("Small! Press any key to try again!\n");
		}
		else
		{
			if( Number == price )
			{
				printf("OK! You are right! Bye Bye!\n");
			}
			else if( Number < price )
			{
				printf("Sorry,Only a little smaller! Press any key to try again!\n");

			}
			else if( Number > price )
				printf(" Sorry, Only a little bigger! Press any key to try again!\n");
		}
		getch();
	}
}