{"action":"opened","issue":{"url":"https://api.github.com/repos/DarminZhou/-list/issues/4","repository_url":"https://api.github.com/repos/DarminZhou/-list","labels_url":"https://api.github.com/repos/DarminZhou/-list/issues/4/labels{/name}","comments_url":"https://api.github.com/repos/DarminZhou/-list/issues/4/comments","events_url":"https://api.github.com/repos/DarminZhou/-list/issues/4/events","html_url":"https://github.com/DarminZhou/-list/issues/4","id":145503718,"number":4,"title":"什么是变量","user":{"login":"DarminZhou","id":16452222,"avatar_url":"https://avatars.githubusercontent.com/u/16452222?v=3","gravatar_id":"","url":"https://api.github.com/users/DarminZhou","html_url":"https://github.com/DarminZhou","followers_url":"https://api.github.com/users/DarminZhou/followers","following_url":"https://api.github.com/users/DarminZhou/following{/other_user}","gists_url":"https://api.github.com/users/DarminZhou/gists{/gist_id}","starred_url":"https://api.github.com/users/DarminZhou/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/DarminZhou/subscriptions","organizations_url":"https://api.github.com/users/DarminZhou/orgs","repos_url":"https://api.github.com/users/DarminZhou/repos","events_url":"https://api.github.com/users/DarminZhou/events{/privacy}","received_events_url":"https://api.github.com/users/DarminZhou/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-04-03T14:06:18Z","updated_at":"2016-04-03T14:06:18Z","closed_at":null,"body":"任务\r\n等差数列可以定义为每一项与它的前一项的差等于一个常数，可以用变量 x1 表示等差数列的第一项，用 d 表示公差，请计算数列\r\n\r\n1 4 7 10 13 16 19 ...\r\n\r\n前 100 项的和。\r\n\r\nx1 = 1\r\nd = 3\r\nn = 100\r\nx100 = x1+(n-1)*d\r\ns = (x1+x100)*n/2\r\nprint s"}}