OJ-Problems-Source/POJ/3225_niuox.cpp

#include <stdio.h>
#include <stdlib.h>

using namespace std;

#define Maxn 132000

//宏定义最好全加上括号
#define lx (x<<1)
#define rx ((x<<1) | 1)
#define MID ((l + r)>>1)

int cover[Maxn<<2];
int XOR[Maxn<<2];
bool vis[Maxn+5];

void FXOR(int x)
{
    if(cover[x]!=-1) cover[x] ^= 1;
    //注意是else
    else XOR[x] ^= 1;
}
void pushDown(int x)
{
    //cover[x] == -1代表x节点的覆盖工作已经结束
    if(cover[x]!=-1)
    {
        cover[lx] = cover[rx] = cover[x];
        XOR[lx] = XOR[rx] = 0;//既然已经覆盖异或标记就清零
        cover[x] = -1;
    }
    if(XOR[x])
    {
        FXOR(lx);
        FXOR(rx);
        XOR[x] = 0;
    }
}

void update(int L,int R,char op,int l,int r,int x)
{
    if(L<=l && r<=R)
    {
        if(op == 'U')
        {
            cover[x] = 1;
            XOR[x] = 0;
        }
        //op == 'I'的情况，由于L<=l && r<=R，所以不需要讨论
        else if(op == 'D')
        {
            cover[x] = 0;
            XOR[x] = 0;
        }
        else if(op == 'C') FXOR(x);
        else if(op == 'S') FXOR(x);
        return;
    }
    pushDown(x);
    if(L<=MID) update(L,R,op,l,MID,lx);
    else if(op == 'I' || op == 'C') cover[lx] = XOR[lx] = 0;
    if(MID<R) update(L,R,op,MID+1,r,rx);
    else if(op == 'I' || op == 'C') cover[rx] = XOR[rx] = 0;
}
//只适合于一次查询
void query(int l,int r,int x)
{
    if(cover[x] == 1)
    {
        for(int i=l; i<=r; i++) vis[i] = true;
        return;
    }
    else if(cover[x] == 0) return;
    if(l == r) return;
    pushDown(x);
    query(l,MID,lx);
    query(MID+1,r,rx);

}

int main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    #endif
    int a,b;
    char op,lchar,rchar;
    XOR[1] = cover[1] = 0;
    while(scanf("%c %c%d,%d%c\n",&op,&lchar,&a,&b,&rchar)!=EOF)
    {
        a<<=1;
        b<<=1;
        if(lchar == '(') a++;
        if(rchar == ')') b--;
        update(a,b,op,0,Maxn,1);
    }
    query(0,Maxn,1);
    int s = -1,e;
    bool flag = false;
    for(int i=0;i<=Maxn;i++)
    {
        if(vis[i] == 1)
        {
            if(s == -1) s = i;
            e = i;
        }
        else
        {
            if(s!=-1)
            {
                if(flag) printf(" ");
                printf("%c%d,%d%c",s&1?'(':'[',s>>1,(e+1)>>1,e&1?')':']');
                s = -1;
                flag = true;
            }
        }
    }
    if(!flag) printf("empty set");
    puts("");
    return 0;
}