首先是开闭区间的处理,我们把\(1.5\)这种数加进来,用\([1.5,6]\)来表示\((2,6]\)
根据离散数学的基本知识,尝试把五个操作转化成人话
把\([x,y]\)变成\(1\)
把\([0,x-1]\)和\([y+1,inf]\)变成\(0\)
把\([x,y]\)变成\(0\)
把\([x,y]\)取反,之后来一个二操作
把\([x,y]\)取反
于是线段树维护一下区间覆盖就好了
记得覆盖标记和取反标记只能同时存在一个就好了
代码
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))
#define LL long long
#define re register
#define maxn 150005
inline int read() {
int x=0,f=0;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='(')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
if(ch==')')f=1;
return x*2-f;
}
char opt[3];
int rev[maxn<<2],tag[maxn<<2];
int d[maxn<<2],l[maxn<<2],r[maxn<<2];
void build(int x,int y,int i) {
l[i]=x,r[i]=y;tag[i]=-1;
if(x==y) return;
int mid=x+y>>1;
build(x,mid,i<<1),build(mid+1,y,i<<1|1);
}
inline void pushdown(int i) {
if(tag[i]!=-1) {
rev[i<<1]=rev[i<<1|1]=0;
tag[i<<1]=tag[i<<1|1]=tag[i];
d[i<<1]=d[i<<1|1]=tag[i];
tag[i]=-1;
}
if(rev[i]) {
d[i<<1|1]^=1,d[i<<1]^=1;
if(tag[i<<1]!=-1) tag[i<<1]^=1;
else rev[i<<1]^=1;
if(tag[i<<1|1]!=-1) tag[i<<1|1]^=1;
else rev[i<<1|1]^=1;
rev[i]=0;
}
}
void change(int x,int y,int val,int i) {
if(x<=l[i]&&y>=r[i]) {
d[i]=val;tag[i]=val;
if(rev[i]) rev[i]=0;
return;
}
pushdown(i);
int mid=l[i]+r[i]>>1;
if(x<=mid) change(x,y,val,i<<1);
if(y>=mid+1) change(x,y,val,i<<1|1);
}
void solve(int x,int y,int i) {
if(x<=l[i]&&y>=r[i]) {
d[i]^=1;
if(tag[i]!=-1) tag[i]^=1;
else rev[i]^=1;
return;
}
pushdown(i);
int mid=l[i]+r[i]>>1;
if(x<=mid) solve(x,y,i<<1);
if(y>=mid+1) solve(x,y,i<<1|1);
}
int query(int pos,int i) {
if(l[i]==r[i]) return d[i];
pushdown(i);
int mid=l[i]+r[i]>>1;
if(pos<=mid) return query(pos,i<<1);
return query(pos,i<<1|1);
}
int main() {
//freopen("a.in","r",stdin);
//freopen("a.out","w",stdout);
build(1,150000,1);
while(scanf("%s",opt)!=EOF) {
int x=read()+2,y=read()+2;
if(opt[0]=='U') change(x,y,1,1);
if(opt[0]=='I') change(1,x-1,0,1),change(y+1,150000,0,1);
if(opt[0]=='D') change(x,y,0,1);
if(opt[0]=='C') change(1,x-1,0,1),change(y+1,150000,0,1),solve(x,y,1);
if(opt[0]=='S') solve(x,y,1);
//if(opt[0]=='I') break;
}
int st=-1,lst=-1,flag=0;
for(re int i=1;i<=150000;i++) {
if(query(i,1)) {
if(st==-1) st=i;
lst=i;
}
else {
if(st!=-1) {
if(flag) putchar(' ');
else flag=1;
if(st&1) putchar('(');
else putchar('[');
printf("%d",st/2-1);
putchar(',');
printf("%d",(lst+1)/2-1);
if(lst&1) putchar(')');
else putchar(']');
}
lst=st=-1;
}
}
if(!flag) puts("empty set");
return 0;
}