实验3

ex1:

 1 # include<math.h> 
 2 # include<stdio.h>
 3 
 4 int main(){
 5     float a,b,c,x1,x2;
 6     float delta,real,imag;
 7     
 8     printf("Enter a,b,c:");
 9     
10     while(scanf("%f%f%f",&a,&b,&c)!=EOF){
11         if (a==0)
12         printf("not quadratic equation.\n\n");
13         else{
14             delta=b*b-4*a*c;
15             
16             if(delta>=0){
17                 x1 = (-b + sqrt(delta)) / (2*a);
18                 x2 = (-b - sqrt(delta)) / (2*a);
19                 printf("x1=%.2f,x2=%.2f\n\n",x1,x2);
20                 }
21         else{
22             real=-b/(2*a);
23             imag=sqrt(-delta)/(2*a);
24             printf("x1=%.2f+%.2fi,x2=%.2f-%.2fi\n\n",real,imag,real,imag);
25             }
26     }
27         printf("Enter a,b,c:");
28 }
29     return 0 ;
30 }

 

 ex2:

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<time.h>
 4 #define N 5
 5 
 6 int main(){
 7     int x,n;
 8     
 9     srand(time(0));
10     n=0;
11     do{
12         n++;
13         x=rand()%10;
14         printf("%3d",x);
15     }while(n<N);
16     printf("\n");
17     
18     return 0;
19 }

 

 ex3:

 1 #include<stdio.h>
 2 #include<math.h>
 3  int main()
 4  {
 5      int m,n,h=0;
 6      for(n=101;n<=200;n++)
 7      {
 8          for(m=2;m<=sqrt(n);++m)
 9          if(n%m==0)break;
10          if(m>sqrt(n))
11          {
12           printf("%5d",n);
13           h++;
14           if(h%5==0)
15           printf("\n");
16           }
17          
18     }
19 
20 printf("\n101~200有%d个素数",h);
21     return 0;
22 }

 

 

 ex4:

 1 #include<stdio.h>
 2 #include<math.h>
 3 int main(){
 4     long m,n,b;
 5     printf("Enter a number:");
 6     while(scanf("%d",&n)!=EOF)
 7     {
 8         int k=0,b=0;
 9         do
10         {
11             m=n%10;
12             if(n%2!=0)
13             {
14                 b=b+m*pow(10,k);
15                 k++;
16             }
17         n=n/10;
18         }while(n!=0);
19     printf("new number is:%d",b);
20     printf("\n\nEnter a number:"); 
21     }
22     return 0;
23 }

 

 

求余数得出各位上的数并除以2判断奇偶,最后用递增的幂数来排列高低位次。

 ex5:

 1 #include<stdio.h>
 2 #include<math.h>
 3 int getfactorial(int n);
 4 int main()
 5 {
 6     int m,n;
 7     float a=0,b=1;
 8     printf("Enter n(1~10):");
 9     while(scanf("%d",&n)!=EOF)
10     {
11          for(m=1;m<=n;m++)
12         { 
13          b=b*m;
14          a=a+pow(-1,m-1)*(1/b);
15         }
16         printf("n=%d,s=%f\n",n,a);
17         printf("\nEnter n(1~10):");
18     }
19     return 0;
20 }
21     

 

 ex6:

 1 #include<stdlib.h>
 2 #include<stdio.h>
 3 #include<time.h>
 4 int main()
 5 {
 6     int m,n,k;
 7     srand(time(0));
 8     k=1+rand()%30;
 9     n=0;
10     printf("猜猜2020年12月哪一天会是你的luck day\n");
11     printf("\n开始喽,你有三次机会,猜吧(1~31):");
12     scanf("%d",&m);
13     while(n<=3)
14     {
15         if(m>k)
16         {
17     
18         printf("\n你猜的日期晚了,luck day悄悄溜到前面啦\n");
19         printf("\n再猜(1~31):");
20         scanf("%d",&m);
21         n++;
22         }
23         else if(m<k)
24         {
25         
26         printf("\n你猜的日期早了,luck day还没到呢\n");
27         printf("\n再猜(1~31);");
28         scanf("%d",&m);
29         n++;
30         }
31         else
32         printf("\n猜中了,nice!");
33         n++;
34     }
35         printf("\n次数用完啦。偷偷告诉你:12月,你的luck day是%d号",k); 
36         return 0; 
37 }

 

posted @ 2020-11-19 00:14  卷心菜投手  阅读(115)  评论(4编辑  收藏  举报