HDU 3397 Sequence operation 线段树

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>

using namespace std;

#define lson rt<<1,l,mid
#define rson rt<<1|1,mid + 1,r
const int maxn = 1e5 + 10;
int lmax[maxn << 2][2], rmax[maxn << 2][2], mmax[maxn << 2][2];
int lazy_xor[maxn << 2], lazy_cover[maxn << 2], sum[maxn << 2];
int N, M, val[maxn];

void swap(int &a, int &b) {
int t = a; a = b; b = t;
}

void change_xor(int rt, int l, int r) {
swap(lmax[rt][0], lmax[rt][1]);
swap(rmax[rt][0], rmax[rt][1]);
swap(mmax[rt][0], mmax[rt][1]);
sum[rt] = r - l + 1 - sum[rt];
}

void change_cover(int rt, int l, int r, int Val) {
for (int i = 0; i < 2; i++)
lmax[rt][i] = rmax[rt][i] = mmax[rt][i] =
Val == i ? r - l + 1 : 0;
sum[rt] = Val * (r - l + 1);
}

void pushup(int rt, int l, int r) {
int lc = rt << 1, rc = rt << 1 | 1, mid = (l + r) >> 1;
int Llen = mid - l + 1, Rlen = r - mid;
for (int i = 0; i < 2; i++) {
lmax[rt][i] = lmax[lc][i];
rmax[rt][i] = rmax[rc][i];
mmax[rt][i] = max(mmax[lc][i], mmax[rc][i]);
if (lmax[rc][i] != 0 && rmax[lc][i] != 0) {
if (lmax[lc][i] == Llen)
lmax[rt][i] += lmax[rc][i];
if (rmax[rc][i] == Rlen)
rmax[rt][i] += rmax[lc][i];
mmax[rt][i] = max(mmax[rt][i], rmax[lc][i] + lmax[rc][i]);
mmax[rt][i] = max(mmax[rt][i], lmax[rt][i]);
mmax[rt][i] = max(mmax[rt][i], rmax[rt][i]);
}
}
sum[rt] = sum[lc] + sum[rc];
}

void pushdown_cover(int rt, int l, int r) {
int lc = rt << 1, rc = rt << 1 | 1, mid = (l + r) >> 1;
lazy_cover[lc] = lazy_cover[rc] = lazy_cover[rt];
lazy_xor[lc] = lazy_xor[rc] = 0;
change_cover(lson, lazy_cover[rt]);
change_cover(rson, lazy_cover[rt]);
lazy_cover[rt] = -1;
}

void pushdown_xor(int rt, int l, int r) {
int lc = rt << 1, rc = rt << 1 | 1, mid = (l + r) >> 1;
if (lazy_cover[lc] == -1) lazy_xor[lc] ^= 1, change_xor(lson);
else lazy_cover[lc] ^= 1, change_cover(lson,lazy_cover[lc]);
if (lazy_cover[rc] == -1) lazy_xor[rc] ^= 1, change_xor(rson);
else lazy_cover[rc] ^= 1, change_cover(rson, lazy_cover[rc]);
lazy_xor[rt] = 0;
}

void pushdown(int rt, int l, int r) {
if (lazy_cover[rt] != -1) pushdown_cover(rt, l, r);
if (lazy_xor[rt] != 0) pushdown_xor(rt, l, r);
}

void build(int rt, int l, int r) {
int mid = (l + r) >> 1;
if (l == r) {
change_cover(rt, l, r, val[l]);
lazy_cover[rt] = -1; lazy_xor[rt] = 0;
sum[rt] = val[l];
}
else {
lazy_cover[rt] = -1; lazy_xor[rt] = 0;
build(lson); build(rson);
pushup(rt, l, r);
}
}

void update(int rt, int l, int r, int ql, int qr, int Val) {
if (ql <= l && qr >= r) {
if (Val == 2) {
if (lazy_cover[rt] == -1) {
change_xor(rt, l, r); lazy_xor[rt] ^= 1;
}
else {
lazy_cover[rt] ^= 1;
change_cover(rt,l,r,lazy_cover[rt]);
}
}
else {
lazy_cover[rt] = Val; lazy_xor[rt] = 0;
change_cover(rt, l, r, lazy_cover[rt]);
}
}
else {
int mid = (l + r) >> 1;
pushdown(rt, l, r);
if (ql <= mid) update(lson, ql, qr, Val);
if (qr > mid) update(rson, ql, qr, Val);
pushup(rt, l, r);
}
}

int query_sum(int rt, int l, int r, int ql, int qr) {
if (ql <= l && qr >= r) return sum[rt];
pushdown(rt, l, r);
int mid = (l + r) >> 1, ret = 0;
if (ql <= mid) ret += query_sum(lson, ql, qr);
if (qr > mid) ret += query_sum(rson, ql, qr);
return ret;
}

int query_len(int rt, int l, int r, int ql, int qr) {
int mid = (l + r) >> 1, lc = rt << 1, rc = rt << 1 | 1;
if (ql <= l && qr >= r) return mmax[rt][1];
pushdown(rt, l, r);
if (ql > mid) return query_len(rson, ql, qr);
if (qr <= mid) return query_len(lson, ql, qr);
//如果最长的连续出现在左边或者右边
int Lmax = query_len(lson, ql, mid), Rmax = query_len(rson, mid + 1, qr);
//或者是出现在中间
int Lpos, Rpos, Mmax;
Lpos = max(ql, mid - rmax[lc][1] + 1);
Rpos = min(qr, mid + lmax[rc][1]);
Mmax = Rpos - Lpos + 1;
return max(Mmax, max(Lmax, Rmax));
}

void Handle(int cmd, int a, int b) {
if (cmd == 0 || cmd == 1 || cmd == 2) update(1, 1, N, a, b, cmd);
if (cmd == 3) printf("%d\n", query_sum(1, 1, N, a, b));
if (cmd == 4) printf("%d\n", query_len(1, 1, N, a, b));
}

int main() {
int T; scanf("%d", &T);
for (int kase = 1; kase <= T; kase++) {
scanf("%d%d", &N, &M);
for (int i = 1; i <= N; i++) scanf("%d", &val[i]);
build(1, 1, N);
for (int i = 0; i < M; i++) {
int cmd, a, b;
scanf("%d%d%d", &cmd, &a, &b);
Handle(cmd, a + 1, b + 1);
}
}
return 0;
}