【BZOJ 1230】 开关灯

【题目链接】

https://www.lydsy.com/JudgeOnline/problem.php?id=1230

【算法】

线段树

【代码】

#include<bits/stdc++.h>
using namespace std;
#define MAXN 100010

int n,m,l,r,opt;

struct Node
{
        int l,r,sum;
        bool tag;
};

class SegmentTree
{
        private :
                Node Tree[MAXN<<];
        public :
              inline void build(int index,int l,int r)
              {
                      int mid;
                      Tree[index].l = l; Tree[index].r = r;
                      Tree[index].sum = ;
                        Tree[index].tag = false;
                      if (l == r) return;
                      mid = (l + r) >> ;
                      build(index<<,l,mid);
                      build(index<<|,mid+,r);
                }
                inline void update(int index)
                {
                        Tree[index].sum = Tree[index<<].sum + Tree[index<<|].sum;
                }
                inline void pushdown(int index)
                {
                        int l = Tree[index].l,r = Tree[index].r;
                        int mid = (l + r) >> ;
                        if (Tree[index].tag)
                        {
                                Tree[index<<].sum = mid - l +  - Tree[index<<].sum;
                                Tree[index<<|].sum = r - mid - Tree[index<<|].sum;
                                Tree[index<<].tag ^= ;
                                Tree[index<<|].tag ^= ;
                                Tree[index].tag = false;
                        }
                }
                inline void modify(int index,int l,int r)
                {
                        int mid;
                        if (Tree[index].l == l && Tree[index].r == r)
                        {
                                Tree[index].sum = r - l +  - Tree[index].sum;
                                Tree[index].tag ^= ;
                                return;
                        } else
                        {
                                pushdown(index);
                                mid = (Tree[index].l + Tree[index].r) >> ;
                                if (mid >= r) modify(index<<,l,r);
                                else if (mid +  <= l) modify(index<<|,l,r);
                                else
                                {
                                        modify(index<<,l,mid);
                                        modify(index<<|,mid+,r);
                                }
                                update(index);
                        }
                }
                inline int query(int index,int l,int r)
                {
                        int mid;
                        if (Tree[index].l == l && Tree[index].r == r) return Tree[index].sum;
                        else
                        {
                                pushdown(index);
                                mid = (Tree[index].l + Tree[index].r) >> ;
                                if (mid >= r) return query(index<<,l,r);
                                else if (mid +  <= l) return query(index<<|,l,r);
                                else return query(index<<,l,mid) + query(index<<|,mid+,r);
                        }
                }
} T;

int main()
{

        scanf("%d%d",&n,&m);
        T.build(,,n);
        while (m--)
        {
                scanf("%d%d%d",&opt,&l,&r);
                if (opt == ) T.modify(,l,r);
                else printf("%d\n",T.query(,l,r));
        }

        return ;

}