Vijos P1881 twinkling stars (strengthen yourself a little more.) ）

Suppose each query is not the entire length, but [x, y] this time interval.

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It's right to feel free to write. This will become the merge scope.

#include <cstdio> #include <cstring> #include <cmath> #include <iostream> #include <queue > #include <algorithm> #define MEM (f) memset (F,0,sizeof (f)) #define M 100005#define mod 1000000007#define Lson o& Lt;<1, L, M#define Rson o<<1|1, m+1, rusing namespace std;typedef long long ll;const int MAX = 0x3f3f3f3f;const I NT MAXN = 200005;int mx_three (int A, int b, int c) {return Max (A, max (b, C));} int n, q, C, X, Y, b[maxn];struct c {int mx, LX, RX;} a[maxn<<2];void build (int o, int l, int r) {A[O].LX =    a[o].mx = A[o].rx = 1;    if (L = = r) return;    int m = (l+r) >> 1;    Build (Lson); Build (Rson);}    C query (int o, int l, int r) {if (x <= l && r <= y) return a[o];    int m = (l+r) >> 1, len = r-l+1;    if (y <= m) return query (Lson);    if (M < x) return query (Rson);    C s, s1, S2;    S1 = query (Lson);    S2 = query (Rson);    S.LX = S1.LX;    S.rx = S2.rx; if (b[m]! = b[m+1]) {if (S.LX = = len-(len>>1)) S.lx + = S2.LX;        if (S.rx = = len>>1) S.rx + = S1.rx;    s.mx = Mx_three (s1.mx, s2.mx, S1.RX+S2.LX);    } else s.mx = Max (s1.mx, s2.mx); return s;}        void update (int o, int l, int r) {if (L = = r) {B[c] ^= 1;    Return    } int m = (l+r) >> 1;    if (c <= m) update (Lson);    else update (Rson);    int len = r-l+1, L = o<<1, r = o<<1|1;    A[O].LX = A[L].LX;    A[o].rx = A[r].rx;        if (b[m]! = b[m+1]) {a[o].mx = Mx_three (a[l].mx, a[r].mx, A[L].RX+A[R].LX);        if (A[O].LX = = len-(len>>1)) A[o].lx + = A[R].LX;    if (A[o].rx = = len>>1) A[o].rx + = A[l].rx; } else a[o].mx = Max (a[l].mx, a[r].mx);}    int main () {scanf ("%d%d", &n, &q);    Build (1, 1, N);        while (q--) {int RR;        scanf ("%d", &AMP;RR);            if (rr = = 2) {scanf ("%d", &c);        Update (1, 1, N);            } else {scanf ("%d%d", &x, &y); printf ("%d\n", Query (1, 1, N). mx);        }} return 0;} 

Vijos P1881 twinkling stars (strengthen yourself a little more.) ）