sum of all integer numbers
时间限制:1000 ms | 内存限制:65535 KB
难度:0
-
描述
- Your task is to find the sum of all integer numbers lying between 1 and N inclusive.
-
输入
- There are multiple test cases.
The input consists of a single integer N that is not greater than 10000 by it's absolute value.
输出 - Write a single integer number that is the sum of all integer numbers lying between 1 and N inclusive. 样例输入
-
3
样例输出 -
6
- There are multiple test cases.
这个题就是求给出的数和1之前所有的整数的和,包括边界,需要注意的就是,可能是负数,所以提前判断一下,交换一下循环的上下限,然后循环累加就行了......看题一定要认真....要不然可能就坑了.....
#include<stdio.h>
int main()
{
int n,i,s,j,a;
while(scanf("%d",&n)!=EOF)
{
s=0;j=1;
if(n<1)
{
j=n;n=1;
}
for(i=j;i<=n;i++)
{
s+=i;
}
printf("%d\n",s);
}
return 0;
}