sum of all integer numbers

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

代码:

#include
      
       
#include
       
         int main() { int n; while(~scanf("%d",&n)) { if(n==0) { printf("1\n"); continue; } int k=1,t=0; if(n<0) k=-1,t=1; n=abs(n); if(n&1) printf("%d\n",((n+1)>>1)*n*k+t); else printf("%d\n",(n>>1)*(n+1)*k+t); } return 0; }
       
      

<script type="text/java script">

<script type="text/java script">BAIDU_CLB_fillSlot("771048");

点击复制链接 与好友分享! 回本站首页

<script> function copyToClipBoard(){ var clipBoardContent=document.title + '\r\n' + document.location; clipBoardContent+='\r\n'; window.clipboardData.setData("Text",clipBoardContent); alert("恭喜您！复制成功"); }

<script>window._bd_share_config={"common":{"bdSnsKey":{},"bdText":"","bdMini":"2","bdMiniList":false,"bdPic":"","bdStyle":"0","bdSize":"24"},"share":{}};with(document)0[(getElementsByTagName('head')[0]||body).appendChild(createElement('script')).src='http://bdimg.share.baidu.com/static/api/js/share.js?v=89860593.js?cdnversion='+~(-new Date()/36e5)];

您对本文章有什么意见或着疑问吗？请到 论坛讨论您的关注和建议是我们前行的参考和动力??

上一篇： UVA 12167 - Proving Equivalences（强连通分量+缩点)

下一篇： BNU25359Escape Time II（状态压缩DP）

相关文章

<script type="text/java script">BAIDU_CLB_fillSlot("182716");

<script type="text/java script">BAIDU_CLB_fillSlot("517916");

图文推荐

<script type="text/java script">BAIDU_CLB_fillSlot("771057");