Codeforces 145E Lucky Queries 线段树

Lucky Queries

感觉是很简单的区间合并， 但是好像我写的比较麻烦。

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define PLL pair<LL, LL>
#define PLI pair<LL, int>
#define PII pair<int, int>
#define SZ(x) ((int)x.size())
#define ull unsigned long long
using namespace std;

const int N = 1e6 + ;
const int inf = 0x3f3f3f3f;
const LL INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9 + ;
const double eps = 1e-;

#define lson l, mid, rt << 1
#define rson mid + 1, r, rt << 1 | 1

struct info {
    int up[][];
    int dn[][];
} a[N << ];

info operator + (const info& a, const info& b) {
    info ans;
    ans.up[][] = a.up[][] + b.up[][];
    ans.up[][] = max(a.up[][] + max(b.up[][], b.up[][]), a.up[][] + b.up[][]);
    ans.up[][] = a.up[][] + b.up[][];
    ans.dn[][] = a.dn[][] + b.dn[][];
    ans.dn[][] = max(a.dn[][] + max(b.dn[][], b.dn[][]), a.dn[][] + b.dn[][]);
    ans.dn[][] = a.dn[][] + b.dn[][];
    return ans;
}

int lazy[N << ];

void change(int rt) {
    swap(a[rt].up[][], a[rt].dn[][]);
    swap(a[rt].up[][], a[rt].dn[][]);
    swap(a[rt].up[][], a[rt].dn[][]);
}

void push(int rt) {
    if(lazy[rt]) {
        change(rt << ); change(rt <<  | );
        lazy[rt << ] ^= ;
        lazy[rt <<  | ] ^= ;
        lazy[rt] = ;
    }
}

void build(int l, int r, int rt) {
    if(l == r) {
        int x; scanf("%1d", &x);
        if(x == ) {
            a[rt].up[][] = ;
            a[rt].up[][] = ;
            a[rt].up[][] = ;
            a[rt].dn[][] = ;
            a[rt].dn[][] = ;
            a[rt].dn[][] = ;
        }
        else {
            a[rt].up[][] = ;
            a[rt].up[][] = ;
            a[rt].up[][] = ;
            a[rt].dn[][] = ;
            a[rt].dn[][] = ;
            a[rt].dn[][] = ;
        }
        return;
    }
    int mid = l + r >> ;
    build(lson); build(rson);
    a[rt] = a[rt << ] + a[rt <<  | ];
}

void update(int L, int R, int l, int r, int rt) {
    if(l >= L && r <= R) {
        lazy[rt] ^= ;
        change(rt);
        return;
    }
    int mid = l + r >> ;
    push(rt);
    if(L <= mid) update(L, R, lson);
    if(R > mid)  update(L, R, rson);
    a[rt] = a[rt << ] + a[rt <<  | ];
}

int n, m;
char s[];

int main() {
    scanf("%d%d", &n, &m);
    build(, n, );
    while(m--) {
        scanf("%s", s);
        if(s[] == 'c') {
            printf("%d\n", max(a[].up[][], max(a[].up[][], a[].up[][])));
        } else {
            int L, R;
            scanf("%d%d", &L, &R);
            update(L, R, , n, );
        }
    }
    return ;
}

/*
*/