C program for sum of powers of numbers

#include<stdio.h>
int main()
{
int a,s;
scanf("%d",&a);
s=((6*a*a*a*a*a)+(15*a*a*a*a)+(10*a*a*a)-a)/30;
printf("%d",s);
return 0;
}

C program for sum of adjacent pairs

#include<stdio.h>
int main()
{
int a,b,s;
scanf("%d %d",&a,&b);
s=0;
while(!(b==-1))
{
s=a+b;
a=b;
scanf("%d",&b);
printf("%d",s);
if(b!=-1)
printf(" ");
if(b==-1)
printf("\n");
}
return 0;
}

C program for inverted right triangle

#include<stdio.h>
int main()
{
int n,i,j,t,m;
scanf("%d",&n);
m=n;
for(i=0;i<m;i++)
  {
  t=i;
for(j=0;j<n;j++)
  {
  i=i+1;
   if(i<=9)
     printf("%d",i);
   if(i>=10)
     printf("%d",i%10);
  }
  n=n-1;
   printf(" \n ");
  i=t;
  }
return 0;
}

C program to find second largest element

#include<stdio.h>
int main()
{
int a,b,temp,t;
scanf("%d%d",&a,&b);
if(a<b)
{
 t=a;
 a=b;
 b=t;
}
scanf("%d",&temp);
while(temp!=-1)
{
 if(temp<b)
 scanf("%d",&temp);
 else if(temp>b)
 {
 b=temp;
 scanf("%d",&temp);
 }
 if(a<b)
 {
 t=a;
 a=b;
 b=t;
 }
}
printf("%d",b);
return 0;
}