水线段树。
/* 380C */
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <deque>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <climits>
#include <cctype>
#include <cassert>
#include <functional>
#include <iterator>
#include <iomanip>
using namespace std;
//#pragma comment(linker,"/STACK:102400000,1024000") #define sti set<int>
#define stpii set<pair<int, int> >
#define mpii map<int,int>
#define vi vector<int>
#define pii pair<int,int>
#define vpii vector<pair<int,int> >
#define rep(i, a, n) for (int i=a;i<n;++i)
#define per(i, a, n) for (int i=n-1;i>=a;--i)
#define clr clear
#define pb push_back
#define mp make_pair
#define fir first
#define sec second
#define all(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define lson l, mid, rt<<1
#define rson mid+1, r, rt<<1|1 const int maxn = 1e6+;
char s[maxn];
int ln[maxn<<];
int rn[maxn<<];
int L, R; inline void PushUp(int rt) {
int lb = rt<<;
int rb = (rt<<)|;
int tmp = min(ln[lb], rn[rb]); ln[rt] = ln[lb] + ln[rb] - tmp;
rn[rt] = rn[lb] + rn[rb] - tmp;
} void build(int l, int r, int rt) {
if (l == r) {
if (s[l] == '(')
ln[rt] = ;
else
rn[rt] = ;
return ;
} int mid = (l+r)>>;
build(lson);
build(rson);
PushUp(rt);
} pii query(int l, int r, int rt) {
if (L<=l && R>=r) {
return mp(ln[rt], rn[rt]);
}
int mid = (l+r)>>;
if (mid < L) {
return query(rson);
} else if (mid >= R) {
return query(lson);
} else {
pii p1 = query(lson);
pii p2 = query(rson);
pii ret;
int tmp = min(p1.fir, p2.sec);
ret.fir = p1.fir + p2.fir - tmp;
ret.sec = p1.sec + p2.sec - tmp;
return ret;
}
} int main() {
ios::sync_with_stdio(false);
#ifndef ONLINE_JUDGE
freopen("data.in", "r", stdin);
freopen("data.out", "w", stdout);
#endif scanf("%s", s+); int n = strlen(s+), m;
pii p;
int ans; build(, n, );
scanf("%d", &m);
while (m--) {
scanf("%d %d", &L, &R);
p = query(, n, );
ans = R-L+-p.fir-p.sec;
printf("%d\n", ans);
} #ifndef ONLINE_JUDGE
printf("time = %d.\n", (int)clock());
#endif return ;
}