Program of sum of 1 to n numbers (Upto 32768):

#include<stdio.h>

#include<conio.h>

void main()

{

int i,s,n;

clrscr();

printf("n Input number::");

scanf("%d",&n);

s=0;

for(i=1;i<=n;i++)

s=s+i;

printf("\n result is 1 to %d=%d",n,s);

getch();

}