AC日记——开关灯 codevs 1690

开关灯

思路：

　　线段树；

　　bool懒标记维护；

　　更新区间时是区间总值减去当前值；

来，上代码：

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

#define maxn 100005

struct TreeNodeType {
    int l,r,dis,lit,mid,flag;
};
struct TreeNodeType tree[maxn<<];

int n,m;

inline void in(int &now)
{
    char Cget=getchar();now=;
    while(Cget>''||Cget<'') Cget=getchar();
    while(Cget>=''&&Cget<='')
    {
        now=now*+Cget-'';
        Cget=getchar();
    }
}

void tree_build(int now,int l,int r)
{
    tree[now].l=l,tree[now].r=r,tree[now].lit=r-l+;
    if(l==r) return ;
    tree[now].mid=l+r>>;
    tree_build(now<<,l,tree[now].mid);
    tree_build(now<<|,tree[now].mid+,r);
}

inline void tree_down(int now)
{
    tree[now<<].flag^=,tree[now<<|].flag^=;
    tree[now<<].dis=tree[now<<].lit-tree[now<<].dis;
    tree[now<<|].dis=tree[now<<|].lit-tree[now<<|].dis;
    tree[now].flag=;
}

void tree_change(int now,int l,int r)
{
    if(tree[now].l==l&&tree[now].r==r)
    {
        tree[now].dis=tree[now].lit-tree[now].dis;
        tree[now].flag^=;
        return ;
    }
    if(tree[now].flag) tree_down(now);
    if(l>tree[now].mid) tree_change(now<<|,l,r);
    else if(r<=tree[now].mid) tree_change(now<<,l,r);
    else
    {
        tree_change(now<<,l,tree[now].mid);
        tree_change(now<<|,tree[now].mid+,r);
    }
    tree[now].dis=tree[now<<].dis+tree[now<<|].dis;
}

int tree_query(int now,int l,int r)
{
    if(tree[now].l==l&&tree[now].r==r) return tree[now].dis;
    if(tree[now].flag) tree_down(now);
    if(l>tree[now].mid) tree_query(now<<|,l,r);
    else if(r<=tree[now].mid) tree_query(now<<,l,r);
    else return tree_query(now<<,l,tree[now].mid)+tree_query(now<<|,tree[now].mid+,r);
}

int main()
{
    in(n),in(m);int op,u,v;
    tree_build(,,n);
    for(;m--;)
    {
        in(op),in(u),in(v);
        if(op) printf("%d\n",tree_query(,u,v));
        else tree_change(,u,v);
    }
    return ;
}