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|1const 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\n", 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;}