Problem A. QAQ
时间限制 1000 ms 内存限制 256 MB"QAQ" is a word to denote an expression of crying. Imagine "Q" as eyes with tears and "A" as a mouth.
Now Diamond has given Bort a string consisting of only uppercase English letters of length n. There is a great number of "QAQ" in the string (Diamond is so cute!).
illustration by 猫屋 https://twitter.com/nekoyaliu
Bort wants to know how many subsequences "QAQ" are in the string Diamond has given. Note that the letters "QAQ" don't have to be consecutive, but the order of letters should be exact.
输入数据
The only line contains a string of length n (1 ≤ n ≤ 100). It's guaranteed that the string only contains uppercase English letters.
输出数据
Print a single integer — the number of subsequences "QAQ" in the string.
样例
样例说明
In the first example there are 4 subsequences "QAQ": "QAQAQYSYIOIWIN", "QAQAQYSYIOIWIN", "QAQAQYSYIOIWIN", "QAQAQYSYIOIWIN".
"); $(this).append($copy); var clipboard = new Clipboard('#' + cpyId, { text: function(trigger) { return document.querySelector('#' + preId).innerText; } }); var isInput = $(this).parent().hasClass("input"); clipboard.on('success', function(e) { if (isInput) { Codeforces.showMessage("The example input has been copied into the clipboard"); } else { Codeforces.showMessage("The example output has been copied into the clipboard"); } e.clearSelection(); }); }); autosize($('.test-explanation textarea')); });