实验二

#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);

 　　return 0;

}

#include<stdio.h>

int main(){

         int year;

         int i;

         printf("input the year");

         scanf("%d",&year);

         if(year % 400 == 0){

                   printf("year:%d,month:2,days:29",year);

         }else if(year % 100 == 0){

                   printf("year:%d,month:2,days:28",year);

         }else if(year % 4 == 0){

                   printf("year:%d,month:2,days:29",year);

         }else

                   printf("year:%d,month:2,days:28",year);

 

         return 0;

}

#include<stdio.h>

int main(){

         int a,b,c;

         scanf("%d%d%d",&a,&b,&c);

         if(a+b<=c||a+c<=b||b+c<=a)

                   printf("不能构成三角形");

         else if(a==b&&b==c)

                   printf("这是一个等边三角形");

         else if(a==b||b==c||a==c)

                   printf("这是一个等腰三角形");

         else if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a)

                   printf("这是一个直角三角形");

         else

                   printf("这是一个一般三角形");

}

#include<stdio.h>

double main(){

         double a,rate,tax,profit;

         scanf("%lf",&a);

         if(a<500)

                   rate = 0;

         else if(a<1000)

                   rate = 0.05;

         else if(a<2000)

                   rate = 0.08;

         else if(a<5000)

                   rate = 0.10;

         else

                   rate = 0.15;

         tax = rate*a;

         profit = a-tax;

         printf("a=%lf  rate=%lf  tax=%lf profit=%lf\n",a,rate,tax,profit);

}

#include<stdio.h>

double main(){

         double a,rate,tax,profit;

         int t;

         scanf("%lf",&a);

         t = a/500;

         switch(t)

         {

                   case 0:rate=0;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;

                   default:rate=0.15;break;

         }

         tax = rate*a;

         profit = a-tax;

         printf("a=%f  rate=%f  tax=%f profit=%f\n",a,rate,tax,profit);

 

        

}