FAFU OJ 求a到b内的元素和输入两个整数a,b(a<=b). 求sum(a,b) = a

求a到b内的元素和

Time Limit:	1000MS	Memory Limit:	65536KB
Total Submissions:	505	Accepted:	388

Description:

输入两个整数a,b(a<=b).
求sum(a,b) = a + a+1 + a+2 + …… + b-2 +b-1 + b.
即区间[a,b]内整数的和。

Input:

输入两个整数a,b(a<=b).

Output:

输出sum(a,b);

Sample Input:

3 5

Sample Output:

Source:

#include <stdio.h>
int main()
{
   int a,b,sum,i;
   scanf("%d%d",&a,&b);
   sum=0;
   if(a>=b)
   {
	   for(i=0;i<=(a-b);i++)
		   sum=sum+(b+i);
   }
   else 
   {
           for(i=0;i<=(b-a);i++)
		   sum=sum+a+i;
   }
   printf("%d",sum);

	return 0;
}