><code class="lang-plain">
			<div class=content><span class=sampledata>5</span></div></code></pre></div></div></div></div></div><div class="row"><div class="column"><h4 class="ui top attached block header">数据范围与提示</h4><div class="ui bottom attached segment font-content"><div style="position: relative; overflow: hidden;">
			<div class=content><p><p><span style="font-size: medium">进行下面五次操作将{X_i}全部变成0：<br /><br />
1. 将X_1,X_2都加上2，变成3 4 1 1 -1。<br /><