【POJ】3225 Help with Intervals

#include<cstdio>
#include<cstring>
#define MAXN 131080
#define INF 987654321
int lazy[MAXN<<2],cover[MAXN<<2];
bool vis[MAXN<<1];
inline void FXOR(int rt)
{
    if(cover[rt]!=-1)
    {
        cover[rt]^=1;
        lazy[rt]=0;
    }
    else
        lazy[rt]^=1;
}
inline void PushDown(int rt)
{
    if(cover[rt]!=-1)
    {
        cover[rt<<1]=cover[rt<<1|1]=cover[rt];
        lazy[rt<<1]=lazy[rt<<1|1]=0;
        cover[rt]=-1;
    }
    else if(lazy[rt])
    {
        FXOR(rt<<1);
        FXOR(rt<<1|1);
        lazy[rt]=0;
    }
}
void Change(int x,int y,int L,int R,int rt)
{
    if(x<=L&&R<=y)
        FXOR(rt);
    else
    {
        int mid=(L+R)>>1;
        PushDown(rt);
        if(mid>=x)
            Change(x,y,L,mid,rt<<1);
        if(y>mid)
            Change(x,y,mid+1,R,rt<<1|1);
    }
}
void Update(int x,int y,int val,int L,int R,int rt)
{
    if(x<=L&&R<=y)
    {
        lazy[rt]=0;
        cover[rt]=val;
    }
    else
    {
        int mid=(L+R)>>1;
        PushDown(rt);
        if(mid>=x)
            Update(x,y,val,L,mid,rt<<1);
        if(y>mid)
            Update(x,y,val,mid+1,R,rt<<1|1);
    }
}
void Query(int L,int R,int rt)
{
    if(cover[rt]==1)
    {
        for(int i=L;i<=R;i++)
            vis[i]=true;
    }
    else if(cover[rt]==-1&&L!=R)
    {
        int mid=(L+R)>>1;
        PushDown(rt);
        Query(L,mid,rt<<1);
        Query(mid+1,R,rt<<1|1);
    }
}
int main()
{
    char ch,left,right;
    int x,y,i,j;
    bool flag;
    memset(cover,0,sizeof(cover));
    memset(lazy,0,sizeof(lazy));
    while(~scanf(" %c %c%d,%d %c",&ch,&left,&x,&y,&right))
    {
        x<<=1;
        y<<=1;
        if(left=='(')
            x++;
        if(right==')')
            y--;
        if(x>y)
            continue;
        if(ch=='U')
            Update(x,y,1,0,MAXN,1);
        else if(ch=='I')
        {
            if(x>0)
                Update(0,x-1,0,0,MAXN,1);
            if(y<MAXN)
                Update(y+1,MAXN,0,0,MAXN,1);
        }
        else if(ch=='D')
            Update(x,y,0,0,MAXN,1);
        else if(ch=='C')
        {
            if(x>0)
                Update(0,x-1,0,0,MAXN,1);
            if(y<MAXN)
                Update(y+1,MAXN,0,0,MAXN,1);
            Change(x,y,0,MAXN,1);
        }
        else
            Change(x,y,0,MAXN,1);
    }
    memset(vis,false,sizeof(vis));
    Query(0,MAXN,1);
    flag=false;
    for(i=0;i<=MAXN;i++)
    {
        if(vis[i])
        {
            for(j=i;j<=MAXN&&vis[j];j++);
            x=i;
            y=j-1;
            if(flag)
                putchar(' ');
            printf("%c%d,%d%c",x&1?'(':'[',x>>1,(y+1)>>1,y&1?')':']');
            flag=true;
            i=j;
        }
    }
    if(flag)
        putchar('\n');
    else
        puts("empty set");
    return 0;
}