P5057 [CQOI2006] 简单题

因为本题和P3870 [TJOI2009] 开关相似，就不写太详细的思路和注释了

#include<bits/stdc++.h>
#define lc rt << 1
#define rc rt << 1 | 1
#define lson lc,l,mid
#define rson rc,mid + 1,r
#define ll long long 
using namespace std;
const int N = 2e5 + 10,inf = 0x3f3f3f3f;
struct node{
    ll sum,alazy,mlazy;
};
node t[N << 2];
int n,m,mod;
int a[N];
void pushup(int rt)
{
    t[rt].sum = (t[lc].sum + t[rc].sum) % mod;
}
void down(int rt,int l,int r)
{
    t[rt].sum = (r - l + 1) - t[rt].sum;
    t[rt].alazy = !t[rt].alazy;
}
void pushdown(int rt,int l,int r)
{
    if(!t[rt].alazy) return;
    int mid = (l + r) / 2;
    down(lson);
    down(rson);
    t[rt].alazy = 0;
}
void build(int rt,int l,int r)
{        
    t[rt].alazy = 0;
    t[rt].sum = 0;
    if(l == r) {
        return;
    }
    int mid = (l + r) / 2;
    build(lson);
    build(rson);
    //pushup(rt);
}
void change(int rt,int l,int r,int x,int y)
{
    if(r < x || y < l) return;
    if(x <= l && r <= y){
        t[rt].sum = (r - l + 1) - t[rt].sum;
        t[rt].alazy = !t[rt].alazy;
        return;
    }
    int mid = (l + r) / 2;
    pushdown(rt,l,r);
    change(lson,x,y);
    change(rson,x,y);
    //pushup(rt);
}

ll query(int rt,int l,int r,int x)
{
    if(r < x || x < l) return -1;
    if(l == r) return t[rt].sum;
    int mid = (l + r) / 2;
    pushdown(rt,l,r);
    return    max(query(lson,x),query(rson,x));
}
int main()
{
    cin >> n >> m;
    //for(int i = 1; i <= n; i++) scanf("%d",&a[i]);
    build(1,1,n);
    //cin >> m;
    while(m--)
    {
        int op;
        ll x,y;
        scanf("%d%lld",&op,&x);
        if(op == 1){
            scanf("%lld",&y);
            change(1,1,n,x,y);
        }
        if(op == 2){
            printf("%lld\n",query(1,1,n,x));
        }
        
    }
    return 0;
}