【CF】223 Div.1 C Sereja and Brackets

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 ;
 }