Constructing a Number Hacker Rank Solution in C, Strange Grid Again Hacker Rank Solution in C, Points on a Line Hacker Rank Solution in C

Strange Grid Again

https://www.hackerrank.com/challenges/strange-grid/problem

#include <stdio.h>
int main()
{
    unsigned long long int r,c;
    scanf("%llu%llu",&r,&c);
    if(r%2 == 0)
    {
        unsigned long long int term = ((r-1)/2)*5+c;
        printf("%llu",2*term-1); // nth term in odd series = 2*n-1
    }
    else{
        unsigned long long int term = ((r)/2)*5+c;
        printf("%llu", 2*term-2); // nth term in even series = 2*n-2
    }
    return 0;
}

Points on a Line

https://www.hackerrank.com/challenges/points-on-a-line/problem

#include <stdio.h>
int main()
{
    int t;
    scanf("%d",&t);
    int x,y,res=0;
    scanf("%d%d",&x,&y);
    t--;
    while(t--)
    {
        int t1,t2;
        scanf("%d%d",&t1,&t2);
        if(!(t1 == x || t2 == y))
            res=1;

    }
    if(res == 1)
        printf("NO");
    else
        printf("YES");
}

Constructing a Number 

https://www.hackerrank.com/challenges/constructing-a-number/problem


Function:
char* canConstruct(int a_count, int* a)
 {
   
              long long int i,sum=0;
              for(i=0;i<a_count;i++)
                          sum=sum+a[i];
              if(sum%3 == 0)
                          return "Yes";
              return "No";
}