对于连续的 $A$,可以使用左边的 $B$ 消除,同时把 $B$ 右移;也可以使用右边的 $B$ 消除,同时把 $B$ 左移。
先考虑什么情况下不能完全消除,字符串的形式应该类似这样:$AAABAAABAAABAAA$,也就是 $x$ 个单独的 $B$,把所有的 $A$ 分成了 $x + 1$ 段,此时只能消除 $x$ 段 $A$,为了获取最大价值,应该留下最小的那段连续的 $A$。
然后考虑什么情况下可以完全消除,只需要在上面的字符串的基础上,添加一个「多余的」$B$ 即可,它的作用只是用来消除最后剩下的那段 $A$,添加方式有三种:在字符串的最开始,在字符串的最后,紧挨着现有的 $B$
// Date: Thu Dec 28 22:27:09 2023
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;
const int INF = 0x3f3f3f3f, MOD = 1e9 + 7;
const double eps = 1e-8;
const int dir[8][2] = {
{0, 1}, {0, -1}, {1, 0}, {-1, 0}, {1, 1}, {1, -1}, {-1, 1}, {-1, -1},
};
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> VI;
typedef pair<int, int> PII;
const ull Pr = 131;
#define For(i, a, b) for (int i = int(a); i < int(b); ++i)
#define Rof(i, a, b) for (int i = int(b) - 1; i >= int(a); --i)
#define For1(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define Rof1(i, a, b) for (int i = int(b); i >= int(a); --i)
#define ForE(i, j) for (int i = h[j]; i != -1; i = ne[i])
#define f1 first
#define f2 second
#define pb push_back
#define has(a, x) (a.find(x) != a.end())
#define nonempty(a) (!a.empty())
#define all(a) (a).begin(), (a).end()
#define SZ(a) int((a).size())
template <typename t> istream &operator>>(istream &in, vector<t> &vec) {
for (t &x : vec)
in >> x;
return in;
}
template <typename t> ostream &operator<<(ostream &out, vector<t> &vec) {
int n = SZ(vec);
For(i, 0, n) {
out << vec[i];
if (i < n - 1)
out << ' ';
}
return out;
}
#ifdef _DEBUG
#define debug1(x) cout << #x " = " << x << endl;
#define debug2(x, y) cout << #x " = " << x << " " #y " = " << y << endl;
#define debug3(x, y, z) \
cout << #x " = " << x << " " #y " = " << y << " " #z " = " << z << endl;
#else
#define debug1
#define debug2
#define debug3
#endif
const int N = 200100;
int n, t, a[N];
string s;
int main(void) {
#ifdef _DEBUG
freopen("1873g.in", "r", stdin);
#endif
std::ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> t;
while (t--) {
cin >> s;
n = SZ(s);
int idx = 0, cnt = 0;
bool flag = false;
For(i, 0, n) {
if (s[i] == 'B') {
if (!flag) {
if ((i == 0) || (i == n - 1) || (i + 1 < n && s[i + 1] == 'B')) {
flag = true;
}
}
if (cnt) {
a[++idx] = cnt;
cnt = 0;
}
} else {
cnt++;
}
}
if (cnt)
a[++idx] = cnt;
ll sum = 0;
int mi_x = INF;
For1(i, 1, idx) {
sum += a[i];
mi_x = min(mi_x, a[i]);
}
if (flag)
cout << sum;
else
cout << (sum - mi_x);
cout << '\n';
}
return 0;
}