CF Educational Round 23 F.MEX Queries

写了3小时 = =。这两天堕落了，昨天也刷了一晚上hihocoder比赛，还爆了零。之后得节制点了，好好准备考研。。

首先很容易想到 压缩数据 + 线段树
然后对于Pushdown真很难写。。需要牵涉到状态修改（所以我又写了一个adjust函数，辅助修改）
我一直跪在test7，因为3号修改在一开始就会出现cover符号的修改，我一开始没有加（比方说1-4都是0,现在 做3 1 4，直接吧1-4的状态改为1就行了）

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <algorithm>
#include <iostream>
#include <map>
#include <set>
#include <queue>
#include <cmath>
using namespace std;
typedef long long ll;
#define lson l,m, rt<<1
#define rson m+1, r, rt<<1|1
const int N = 2e5+5;
const int INF = 0x3f3f3f3f;

int a[N]; ll b[N], c[N];
ll has[N << 1];
map<ll, int> mp;

int sum[N << 2];
int cover[N << 2];

void adjust(int rt) {
    if(cover[rt] == 0) cover[rt] = -2;
    else if(cover[rt] == -2) cover[rt] = 0;
    else cover[rt] *= -1;
} 

void Pushdown(int rt, int len) {
    if(cover[rt] != 0) {
        if(cover[rt] == 1) {
            cover[rt << 1] = cover[rt << 1|1] = cover[rt];
            sum[rt << 1] = (len+1) / 2;
            sum[rt << 1|1] = len / 2;
        }else if(cover[rt] == -1) {
            cover[rt << 1] = cover[rt << 1|1] = cover[rt];
            sum[rt << 1] = 0;
            sum[rt << 1|1] = 0;
        }else {
            sum[rt << 1] = (len+1) / 2 - sum[rt << 1];
            sum[rt << 1|1] = len / 2 - sum[rt << 1|1];

            adjust(rt << 1); adjust(rt << 1|1); 
        }
        cover[rt] = 0;
    }
}

void Add(int L, int R, int l, int r, int rt) {
    if(sum[rt] == r-l+1) return;
    if(L <= l && r <= R) {
        sum[rt] = r-l+1;
        cover[rt] = 1;
        return ;
    }
    int m = (l + r) >> 1;
    Pushdown(rt, r-l+1);
    if(L <= m) Add(L, R, lson); 
    if(R > m)  Add(L, R, rson);
    sum[rt] = sum[rt << 1] + sum[rt << 1|1];
}
void Delete(int L, int R, int l, int r, int rt) {
    if(sum[rt] == 0) return;
    if(L <= l && r <= R) {
        sum[rt] = 0;
        cover[rt] = -1;
        return;
    }
    int m = (l + r) >> 1;
    Pushdown(rt, r-l+1);

    if(L <= m) Delete(L, R, lson); 
    if(R > m)  Delete(L, R, rson);
    sum[rt] = sum[rt << 1] + sum[rt << 1|1];
}
void Invert(int L, int R, int l, int r, int rt) {
    if(L <= l && r <= R) {
        adjust(rt);
        sum[rt] = (r-l+1) - sum[rt];
        return;
    }
    int m = (l + r) >>1;
    Pushdown(rt, r-l+1);
    if(L <= m) Invert(L, R, lson);
    if(R > m) Invert(L, R, rson);
    sum[rt] = sum[rt << 1] + sum[rt << 1|1];
}
int suc = 0;
void Find(int l, int r, int rt) {
    if(suc) return;
    if(sum[rt] == r-l+1) return;
    else if(sum[rt] == 0) {
        printf("%lld
", has[l-1]); suc = 1; return;
    }
    Pushdown(rt, r-l+1);
    int m = (l + r) >>1;
    Find(lson); Find(rson);
}

int main() {
    int q;
    while(~scanf("%d", &q)) {
        mp.clear();
        memset(sum, 0, sizeof(sum));
        memset(cover, 0, sizeof(cover));

        int tot = 0;
        has[tot ++] = 1;
        for(int i = 0; i < q; ++i) {
            scanf("%d %lld %lld", &a[i], &b[i], &c[i]);
            has[tot ++ ] = b[i]; has[tot ++ ] = c[i]+1; 
        }   
        sort(has, has + tot);
        tot = unique(has, has + tot) - has;
        for(int i = 0; i < tot; ++i) {
            mp[has[i]] = i+1;
            //  printf("%lld ", has[i]);
        }

        for(int i = 0; i < q; ++i) {
            if(a[i] == 1) {
                Add(mp[b[i]], mp[c[i]+1]-1, 1, tot, 1);
            }else if(a[i] == 2) {
                Delete(mp[b[i]], mp[c[i]+1]-1, 1, tot, 1);
            }else Invert(mp[b[i]], mp[c[i]+1]-1, 1, tot, 1);
            suc = 0; Find(1, tot, 1);
        }


    }
    return 0;
}