实验二

一

#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;

 

}

 二

#include<stdio.h>

int main(){

         int year;

         printf("input the year");

         scanf("%d",&year);

         if(year%4==0&&year%100!=0||year%400==0)

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

         else

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

         return 0;

}

三

#include<stdio.h>

#include<stdlib.h>

int main(){

         int a, b, c;         printf("input three numbers:\n");   scanf("%d", &a);      scanf("%d", &b);      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)                   {                                   

         printf("equilateral triangle\n");                          }                          

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

         printf("isosceles  right triangle\n");                         }                          

         else                    {                                   

         printf("isosceles triangle\n");                    }                 }                

         else if(a * a + b * b == c * c || a * a + c * c == b * b || b * b + c * c == a * a)            {                           printf("right triangle\n");                   }                

         else           {                          

         printf("ordinary triangle\n");            }        }       

         else  {                

         printf("unable to get a triangle\n");        }       

         system("pause");   

 

return 0;}

 四

#include <stdio.h>

#include <math.h>

int main(){

         double a,rate,tax,profit;

         scanf("%lf",&a);

         if(a>=5000){

                   rate = 0.15;}

         else if(2000<=a<5000){

                   rate = 0.10;}

         else if(1000<=a<2000){

                   rate = 0.08;}

         else if(500<=a<1000){

                   rate = 0.05;}

         else{

                   rate = 0.00;}

         tax = a*rate;

         profit = a - tax;

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

return 0;

}