C language exercises

1.        

#include<stdio.h>
int main()
{
  printf("Programming in C is fun!\n"); 
return 0;
}

2.

#include<stdio.h>
int main()
{
  printf("* * * *\n");
  printf(" * * *\n");
  printf("  * *\n");
  printf("   *\n");
  return 0;
}

 3.

#include<stdio.h>
int main()
{
  int F=150;
  printf("fahr = 150, celsius = %d\n",5*(F-32)/9);
return 0;
  
}

4.

#include<stdio.h>
#include<math.h>
int main()
{
  int g=10;
  int t=3;
  printf("height = %.2lf\n",(double)(g/2*(int)pow(t,2)));
retrun 0;
}

5.

#include<stdio.h>
int main()
{
  
  int c;
  scanf("%d\n",&c);
  printf("Celsius = %d\n",5*(c-32)/9);
return 0;
}

6.

#include<stdio.h>
int main()
{
  int m,n;
  scanf("%d %d\n",&m,&n);
  if(n!=0){
  printf("%d + %d = %d\n",m,n,m+n);
  printf("%d - %d = %d\n",m,n,m-n);
  printf("%d * %d = %d\n",m,n,m*n);
  printf("%d / %d = %d\n",m,n,m/n);
    
  }
  return 0;
}

7.

#include<stdio.h>
int main()
{
  double x;
  scanf("%lf\n",&x);
  if(x==0) printf("f(%.1lf) = %.1lf\n",x,x);
  else printf("f(%.1lf) = %.1lf\n",x,1/x);
  return 0;
}

8.

#include<stdio.h>
#include<math.h>
int main()
{
  double x;
  scanf("%lf\n",&x);
  if(x>=0) printf("f(%.2lf) = %.2lf\n",x,pow(x,0.5));
  else printf("f(%.2lf) = %.2lf\n",x,pow(x+1,2)+2.0*x+1/x);
  return 0;
}

9.

#include<stdio.h>
int main()
{
  int lower,upper;
  int i;
  scanf("%d %d",&lower,&upper);
  if(lower<=upper)
    {
      printf("fahr celsius\n");
      for(i=lower;i<=upper;i+=2)
      {
        printf("%d%6.1lf\n",i,(double)(5.0*(i-32)/9.0));
      }

    }
    else printf("Invalid.\n");
  return 0;
}

10.

#include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  int i;
  double sum=0.0;
  for(i=1;i<=n;i++)
  {
    sum+=1.0/i;
  }
  printf("sum = %.6lf\n",sum);
  return 0;
}

11.

#include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  int i;
  double sum=0.0;
  int d=1;
  for(i=1;i<=n;i++)
  {
    sum+=1.0/d;
    d+=2;
  }
  printf("sum = %.6lf\n",sum);
  return 0;
}

12.

#include<stdio.h>
int main()
{
  int n;
  int l=1;
  scanf("%d",&n);
  int i;
  double sum=0.0;
  int d=1;
  for(i=1;i<=n;i++)
  {
    sum+=1.0/d*l;
    d+=3;
    l=-l;
  }
  printf("sum = %.3lf\n",sum);
  return 0;
}

13.

#include<stdio.h>
#include<math.h>
int main()
{
  int n;
  scanf("%d",&n);
  int i;
  for(i=0;i<=n;i++)
  {
    printf("pow(3,%d) = %d\n",i,(int)pow(3,i));
  }
  return 0;
}

14.

#include<stdio.h>
double fun(int n)
{
    int i;
    double t=1.0;
    for(i=1;i<=n;i++)
    {
        t*=i;
    }
    return t;
}
int main()
{
    int m,n;
    scanf("%d %d",&m,&n);
    double result=fun(n)/(fun(m)*fun(n-m));
    printf("result = %.0lf\n",result);
}

15.

#include<stdio.h>
int main()
{
  int a1,a2,a3,a4;
  scanf("%d %d %d %d",&a1,&a2,&a3,&a4);
  printf("Sum = %d; Average = %.1lf\n",a1+a2+a3+a4,(double)(a1+a2+a3+a4)/4.0);
  return 0;

}

16.

#include<stdio.h>
int main()
{
    int n;
    scanf("%d",&n);
    if(n<=50)
    {
        if(n<0) printf("Invalid Value!\n");
        else printf("cost = %.2lf\n",n*0.53);
    }
    else printf("cost = %.2lf\n",(50*0.53)+(n-50)*(0.53+0.05));
    return 0;
}

17.

#include<stdio.h>
int main()
{
    int m,n;
    scanf("%d %d",&m,&n);
    int i;
    if(m<=n&&m!=0&&n!=0){
    double sum=0.0;
    for(i=m;i<=n;i++)
    {
        sum+=(double)pow(i,2)+1.0/i;
    }
    printf("sum = %.6lf\n",sum);}
    return 0;
}

18.

#include<stdio.h>
int main()
{
    int n;
    scanf("%d",&n);
    int i;
    if(n!=0){
    double sum=0.0;
    int t1=1;
    int t2=1;
    int temp=1;
    for(i=1;i<=n;i++)
    {
        sum+=((double)t1/t2)*temp;
        t1++;
        t2+=2;
        temp=-temp;
    }
    printf("%.3lf\n",sum);}
    return 0;
}

19.

#include<stdio.h>
#include<math.h>
int main()
{
    int n;
    scanf("%d",&n);
    int i;
  if(n!=0){
    double sum=0.0;
    for(i=1;i<=n;i++)
    {
        sum+=sqrt((double)i);
    }
    printf("sum = %.2lf\n",sum);
    }
    return 0;
}

20.

#include<stdio.h>
#include<math.h>
int main()
{
    int n;
    scanf("%d",&n);
    int i;
   if(n!=0){
    long long sum=0;
    for(i=1;i<=n;i++)
    {
        sum+=fun(i);
    }
    printf("%lld\n",sum);
    }
    return 0;
}

int fun(int n)
{
    int i;
    long long t=1;
    for(i=1;i<=n;i++)
    {
        t=t*i;
    }
  printf("t=%lld\n",t);
    return t;
}

21.

#include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  if(n>=0)
  {
    if(n>0) printf("sign(%d) = 1\n",n);
    else printf("sign(%d) = 0\n",n);
  }
  else printf("sign(%d) = -1\n",n);
return 0;
}

22.

#include<stdio.h>
int main()
{
    char str[10];
    int i;
    int letter=0;
    int blank=0;
    int digit=0;
    int other=0;
    for(i=0;i<10;i++)
    {
       scanf("%c",&str[i]);
       if(str[i]>='a'&&str[i]<='z'||str[i]>='A'&&str[i]<='Z') letter++;
       else if(str[i]==' '||str[i]=='\n') blank++;
       else if(str[i]>='0'&&str[i]<='9') digit++;
       else other++;
    }
    printf("letter = %d, blank = %d, digit = %d, other = %d\n",letter,blank,digit,other);
    return 0;
}

23.

#include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  if(n>=2001&&n<=2100)
  {
    int temp=0;
    int i;
    for(i=2001;i<=n;i++)
    {
      if((i%4==0&&i%100!=0)||i%400==0)
      {printf("%d\n",i);temp++;}
    }
    if(temp==0) printf("None\n");
  }
  else
  printf("Invalid year!\n");
  return 0;
}

24.

#include<stdio.h>
int main()
{
int n;
scanf("%d",&n);
{
if(n>=90)
printf("A\n);
{
if(n>=80)
printf("B\n);
{
if(n>=70)
printf("C\n");
{
if(n>=60)
printf("D\n");
}
}
}
}

return 0;
}

25.