hdu 3397

一些放的错误，写给自己看

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

#define lson rt << 1, l, m
#define rson rt << 1 | 1, m + 1, r
#define rclen (curlen >> 1)
#define lclen (curlen - rclen)
#define getMid (l + r) >> 1
using namespace std;

typedef long long ll;
const int MAXN = 100005;
int N, M;
int maxlen[MAXN << 2];
int llen[MAXN << 2];
int rlen[MAXN << 2];
int cover[MAXN << 2];
int num[MAXN << 2];
char ch[MAXN];



void push_up(int rt, int l, int r)
{
	int curlen = r - l + 1;
	llen[rt] = llen[rt << 1];
	rlen[rt] = rlen[rt << 1 | 1];
	if (llen[rt] == lclen)
		llen[rt] += llen[rt << 1 | 1];
	if (rlen[rt] == rclen)
		rlen[rt] += rlen[rt << 1];
	maxlen[rt] = max(rlen[rt << 1] + llen[rt << 1 | 1], max(maxlen[rt << 1], maxlen[rt << 1 | 1]));
	num[rt] = num[rt << 1] + num[rt << 1 | 1];
}

void push_down(int rt, int l, int r)
{
	int curlen = r - l + 1;
	if (cover[rt] != -1)
	{
		cover[rt << 1] = cover[rt << 1 | 1] = cover[rt];
		num[rt << 1] = llen[rt << 1] = rlen[rt << 1] = maxlen[rt << 1] = cover[rt] ? lclen : 0;
		num[rt << 1 | 1] = llen[rt << 1 | 1] = rlen[rt << 1 | 1] = maxlen[rt << 1 | 1] = cover[rt] ? rclen : 0;
		cover[rt] = -1;
	}
}

void build(int rt, int l, int r)
{
	cover[rt] = -1;
	if (l == r)
	{
		scanf(" %c", &ch[l]);
 		cover[rt] = num[rt] = llen[rt] = rlen[rt] = maxlen[rt] = ch[l] == '1' ? 1 : 0;
		return;
	}
	int m = getMid;
	build(lson);
	build(rson);
	push_up(rt, l, r);
}

void Xor(int L, int R, int rt, int l, int r)
{
	if (L <= l && r <= R && cover[rt] != -1)
	{
		cover[rt] ^= 1;
		num[rt] = llen[rt] = rlen[rt] = maxlen[rt] = cover[rt] == 1 ? (r - l + 1) : 0;
		return;
	}
	push_down(rt, l, r);
	int m = getMid;
	if (L <= m)
		Xor(L, R, lson);
	if (R > m)
		Xor(L, R, rson);
	push_up(rt, l, r);
}

void updata(int op, int L, int R, int rt, int l, int r)
{
	if (L <= l && r <= R)
	{
		cover[rt] = op;
		num[rt] = llen[rt] = rlen[rt] = maxlen[rt] = op == 1 ? (r - l + 1) : 0;
		return;
	}
	push_down(rt, l, r);
	int m = getMid;
	if (L <= m)
		updata(op, L, R, lson);
	if (R > m)
		updata(op, L, R, rson);
	push_up(rt, l, r);
}

int query_num(int L, int R, int rt, int l, int r)
{
	if (L <= l && r <= R)
		return num[rt];
	int ret = 0;
	push_down(rt, l, r);
	int m = getMid;
	if (L <= m)
		ret += query_num(L, R, lson);
	if (R > m)
		ret += query_num(L, R, rson);
	push_up(rt, l, r);
	return ret;
}

int query_l(int L, int R, int rt, int l, int r)
{
	if (L <= l && r <= R)
		return maxlen[rt];
	push_down(rt, l, r);
	int m = getMid;
	int ret = 0;
	/*if (L <= m)
		ret = max(ret, query_l(L, R, lson));
	if (R > m)
		ret = max(ret, query_l(L, R, rson));
	int t = min(rlen[rt << 1], m - L + 1) + min(llen[rt << 1 | 1], R - m);这样写会出现R - m, m - L - 1小于零的情况
	*/
	
	if (L > m)
		ret = query_l(L, R, rson);
	else if (R <= m)
		ret = query_l(L, R, lson);
	else
	{
		int a = query_l(L, R, lson);
		int b = query_l(L, R, rson);
		int c = min(rlen[rt << 1], m - L + 1) + min(llen[rt << 1 | 1], R - m);
		ret = max(max(a, b), c);
	}
	
	push_up(rt, l, r);
	return ret;
}

int main(void)
{
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w", stdout);
	int T, op, a, b;
	int n, m;
	scanf("%d", &T);
	while (T--)
	{
		scanf("%d %d", &n, &m);
		build(1, 0, n - 1);
		while (m--)
		{
			scanf("%d %d %d", &op, &a, &b);
			if (op < 2)
				updata(op, a, b, 1, 0, n - 1);
			else if (op == 2)
				Xor(a, b, 1, 0, n - 1);
			else if (op == 3)
				printf("%d\n", query_num(a, b, 1, 0, n - 1));
			else
				printf("%d\n", query_l(a, b, 1, 0, n - 1));
		}
	}
	return 0;
}