#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
inline int read(){
    int x = 0,f = 1;
    char ch = getchar();
    while(ch < '0' || ch > '9'){
        if(ch == '-')
            f = -1;
        ch = getchar();
    }
    while(ch >= '0' && ch <= '9'){
        x = (x << 1) + (x << 3) + (ch ^ 48);
        ch = getchar();
    }
    return x * f;
}
char s[100005];
int m, x, y, tim, id[100005], ans[100005], cnt, tmp, tot, fa[100005], in[100005], out[100005], T[100005];
struct TRIE{
	int d[27], fail; 
}t[100005];
vector<int> d[100005];
vector< pair<int, int> > Q[100005];
void add(int x, int y){
	for(; x <= tot; x += (x & (-x))) T[x] += y;
}
int query(int x){
	int res = 0;
	for(; x; x -= (x & (-x))) res += T[x];
	return res;
}
void dfs(int x){
	in[x] = ++tim;
	for(int i = 0; i < d[x].size(); ++i){
		dfs(d[x][i]);
	}
	out[x] = tim;
}
int main(){
	scanf("%s", s + 1);
	for(int i = 1; s[i]; ++i){
		if(s[i] >= 'a' && s[i] <= 'z'){
			if(!t[tmp].d[s[i] - 'a']){
				t[tmp].d[s[i] - 'a'] = ++tot;
				fa[tot] = tmp;
				tmp = tot;
			}
			else tmp = t[tmp].d[s[i] - 'a'];
		}
		if(s[i] == 'P'){
			id[++cnt] = tmp;
		}
		if(s[i] == 'B') tmp = fa[tmp];
	}
	queue<int> q;
	for(int i = 0; i <= 25; ++i) if(t[0].d[i]) q.push(t[0].d[i]);
	while(q.size()){
		int x = q.front(); q.pop();
		for(int i = 0; i <= 25; ++i){
			if(t[x].d[i]){
				q.push(t[x].d[i]);
				t[t[x].d[i]].fail = t[t[x].fail].d[i];
			}
			else{
				t[x].d[i] = t[t[x].fail].d[i];
			}
		}
	}
	for(int i = 1; i <= tot; ++i){
		d[t[i].fail].push_back(i);
	}
	dfs(0);
	m = read();
	for(int i = 1; i <= m; ++i){
		int p, q;
		p = read(), q = read();
		Q[q].push_back(make_pair(p, i));
	}
	tmp = 0; int now = 0;
	for(int i = 1; s[i]; ++i){
		if(s[i] >= 'a' && s[i] <= 'z'){
			tmp = t[tmp].d[s[i] - 'a']; add(in[tmp], 1);
		}
		if(s[i] == 'B'){
			add(in[tmp], -1);
			tmp = fa[tmp];
		}
		if(s[i] == 'P'){
			now++;
			for(int j = 0; j < Q[now].size(); ++j){
				ans[Q[now][j].second] = query(out[id[Q[now][j].first]]) - query(in[id[Q[now][j].first]] - 1);
			}
		} 
	}
	for(int i = 1; i <= m; ++i) printf("%d\n", ans[i]);
	return 0;
}

实现思路和一篇题解相似，但是找不出问题，请大佬帮忙看下/bx