PAT/source/html/a1093.html

Count PAT's
<div class="ques-view"><p>The string <code>APPAPT</code> contains two <code>PAT</code>'s as substrings. The first one is formed by the 2nd, the 4th, and the 6th characters, and the second one is formed by the 3rd, the 4th, and the 6th characters.</p>
<p>Now given any string, you are supposed to tell the number of <code>PAT</code>'s contained in the string.</p>
<h3 id="input-specification-">Input Specification:</h3>
<p>Each input file contains one test case. For each case, there is only one line giving a string of no more than <span class="katex"><span class="katex-mathml"><math><mrow><mn>1</mn><msup><mn>0</mn><mn>5</mn></msup></mrow>10^5</math></span><span aria-hidden="true" class="katex-html"><span class="strut" style="height:0.8141079999999999em;"></span><span class="strut bottom" style="height:0.8141079999999999em;vertical-align:0em;"></span><span class="base textstyle uncramped"><span class="mord mathrm">1</span><span class="mord"><span class="mord mathrm">0</span><span class="msupsub"><span class="vlist"><span style="top:-0.363em;margin-right:0.05em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="reset-textstyle scriptstyle uncramped mtight"><span class="mord mathrm mtight">5</span></span></span><span class="baseline-fix"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span>​</span></span></span></span></span></span></span> characters containing only <code>P</code>, <code>A</code>, or <code>T</code>.</p>
<h3 id="output-specification-">Output Specification:</h3>
<p>For each test case, print in one line the number of <code>PAT</code>'s contained in the string. Since the result may be a huge number, you only have to output the result moded by 1000000007.</p>
<h3 id="sample-input-">Sample Input:</h3>
<pre><code class="lang-in">APPAPT
</code></pre>
<h3 id="sample-output-">Sample Output:</h3>
<pre><code class="lang-out">2
</code></pre>
</div>