Codeforces Round #447 (Div. 2) A. QAQ【三重暴力枚举】

A. QAQ
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

"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!).

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.

Input

The only line contains a string of length n (1 ≤ n ≤ 100). It's guaranteed that the string only contains uppercase English letters.

Output

Print a single integer — the number of subsequences "QAQ" in the string.

Examples
input
QAQAQYSYIOIWIN
output
4
input
QAQQQZZYNOIWIN
output
3
Note

In the first example there are 4 subsequences "QAQ": "QAQAQYSYIOIWIN", "QAQAQYSYIOIWIN", "QAQAQYSYIOIWIN", "QAQAQYSYIOIWIN".

【题意】:含QAQ的序列有多少(不要求连续)。

【分析】:三重循环枚举。

【代码】:

#include <bits/stdc++.h>

using namespace std;

const int maxn = 110;
int main()
{
    char a[maxn];
    int ans;
    gets(a+1);//注意+1!因为从1开始!!!
    int n=strlen(a+1);
        ans=0;
        for(int i=1;i<=n;i++)
        {
            for(int j=i+1;j<=n;j++)
            {
                for(int k=j+1;k<=n;k++)
                {
                    if(a[i]=='Q'&&a[j]=='A'&&a[k]=='Q')
                    {
                        ans++;
                    }
                }
            }
        }
        printf("%d\n",ans);
    return 0;
}
枚举

 

posted @ 2017-11-20 14:02  Roni_i  阅读(202)  评论(0编辑  收藏  举报