【wikioi1690】 开关灯

#include<iostream>#include<cstdio>using namespace std;struct data{int l,r,sum;bool tag;}tr[2000001];int n,m;void build(int k,int s,int t){     tr[k].l=s;tr[k].r=t;     if(s==t)return;     int mid=(s+t)>>1;     build(k<<1,s,mid);     build(k<<1|1,mid+1,t);}void pushdown(int k){        if(!tr[k].tag)return;     tr[k<<1].tag=!tr[k<<1].tag;     tr[k<<1|1].tag=!tr[k<<1|1].tag;     tr[k<<1].sum=tr[k<<1].r-tr[k<<1].l+1-tr[k<<1].sum;     tr[k<<1|1].sum=tr[k<<1|1].r-tr[k<<1|1].l+1-tr[k<<1|1].sum;     tr[k].tag=0;}void update(int k,int x,int y){ pushdown(k);     int l=tr[k].l,r=tr[k].r;     if(l==x&&r==y)     {          tr[k].sum=y-x+1-tr[k].sum;          if(l!=r)tr[k].tag=1;          return;          }     int mid=(l+r)>>1;     if(mid>=y)update(k<<1,x,y);     else if(mid<x)update(k<<1|1,x,y);     else {update(k<<1,x,mid);update(k<<1|1,mid+1,y);}     tr[k].sum=tr[k<<1].sum+tr[k<<1|1].sum;}int ask(int k,int x,int y){pushdown(k);    int l=tr[k].l,r=tr[k].r;    if(l==x&&y==r)return tr[k].sum;    int mid=(l+r)>>1;    if(mid>=y)return ask(k<<1,x,y);    else if(mid<x)return ask(k<<1|1,x,y);    else return (ask(k<<1,x,mid)+ask(k<<1|1,mid+1,y));}int main(){scanf("%d %d",&n,&m);build(1,1,n);for(int i=1;i<=m;i++){int temp,x,y;scanf("%d %d %d",&temp,&x,&y);if(temp==0)update(1,x,y);else printf("%d\n",ask(1,x,y));}return 0;}