实验二（18网三43号袁昳）

#include <stdio.h>
int main()
{
char a,b,c,d,e;
a=getchar();
b=getchar();
c=getchar();
d=getchar();
e=getchar();
putchar(a);
putchar(b);
putchar(c);
putchar(d);
putchar(e);
printf("
");
return 0;
}

#include <stdio.h>
int main()
{
int year,month,days;
month=2;
printf("input the year:");
scanf("%d",&year);
if ((year%4==0&&year%100!=0)||(year%400==0&&year%100==0))
{
    days=29;
    printf("year:%d,month:2,days:%d
",year,days);
}

else
{
    days=28;
    printf("year:%d,month:2,days:%d
",year,days);
}

return 0;
}

#include <stdio.h>
int main()
{
int a,b,c;
printf("input a:");
scanf("%d",&a);
printf("input b:");
scanf("%d",&b);
printf("input c:");
scanf("%d",&c);

if (a+b>c&&a+c>b&&b+c>a)
{
    if(a==b||a==c||b==c)
    {
        if(a==b&&b==c&&a==c)
        {    
            printf("等边三角形
");
        }
        else
        {
            printf("等腰三角形
");
        }
    }
    

    else if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a)
    {
        printf("直角三角形
");
    }
    else
    {
        printf("一般三角形
");
    }
}

else
{
    printf("无法组成三角形
");
}
return 0;
}

#include <stdio.h>
int main()
{
double a,rate,tax,profit;
printf("input a:");
scanf("%lf",&a);
if (a<500)
{
    rate=0.00;
}
else if (a>=500&&a<1000)
{
    rate=0.05;
}
else if (a>=1000&&a<2000)
{
    rate=0.08; 
}
else if (a>=2000&&a<5000)
{
    rate=0.10;
}
else if (5000<=a)
{
    rate=0.15; 
}
tax=a*rate;
profit=a-tax;
printf("a=%lf
",a);
printf("rate=%lf
",rate);
printf("tax=%lf
",tax);
printf("profit=%lf
",profit);
return 0;
}

#include <stdio.h>
int main()
{
double a,rate,tax,profit;
printf("input a:");
scanf("%lf",&a);

if (a>=5000)
{
rate=0.15;
}
int b;
b=a;
switch (b/500)
{
    case 0:
        rate=0.00;
        break;
    case 1:
        rate=0.05;
        break;
    case 2:
        rate=0.08;
        break;
    case 3:
        rate=0.08;
        break;
    case 4:
        rate=0.10;
        break;
    case 5:
        rate=0.10;
        break;
    case 6:
        rate=0.10;
        break;
    case 7:
        rate=0.10;
        break;
    case 8:
        rate=0.10;
        break;
    case 9:
        rate=0.10;
        break;
}



tax=a*rate;
profit=a-tax;
printf("a=%lf
",a);
printf("rate=%lf
",rate);
printf("tax=%lf
",tax);
printf("profit=%lf
",profit);
return 0;
}