codevs 1191 数轴染色 区间更新加延迟标记

#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<queue>
#include<algorithm>
#include<stack>
#include<cstring>
#include<vector>
#include<list>
#include<set>
#include<map>
#define true ture
#define false flase
using namespace std;
#define ll long long
int scan()
{
    int res = 0 , ch ;
    while( !( ( ch = getchar() ) >= ‘0‘ && ch <= ‘9‘ ) )
    {
        if( ch == EOF )  return 1 << 30 ;
    }
    res = ch - ‘0‘ ;
    while( ( ch = getchar() ) >= ‘0‘ && ch <= ‘9‘ )
        res = res * 10 + ( ch - ‘0‘ ) ;
    return res ;
}
struct is
{
    int l,r;
    int num;
    int lazy;
}tree[200010*3];
void build_tree(int l,int r,int pos)
{
    tree[pos].l=l;
    tree[pos].r=r;
    tree[pos].lazy=-1;
    if(l==r)
    {
        tree[pos].num=1;
        //scanf("%lld",&tree[pos].num);
        return;
    }
    int mid=(l+r)/2;
    build_tree(l,mid,pos*2);
    build_tree(mid+1,r,pos*2+1);
    tree[pos].num=tree[pos*2].num+tree[pos*2+1].num;
}
void update(int l,int r,int change,int pos)
{
    if(tree[pos].l==l&&tree[pos].r==r)
    {
        tree[pos].lazy=change;
        tree[pos].num=0;
        return;
    }
    if(tree[pos].lazy==0)
    {
        tree[pos*2].num=(tree[pos*2].r+1-tree[pos*2].l)*tree[pos].lazy;
        tree[pos*2+1].num=(tree[pos*2+1].r+1-tree[pos*2+1].l)*tree[pos].lazy;
        tree[pos*2].lazy=tree[pos].lazy;
        tree[pos*2+1].lazy=tree[pos].lazy;
        tree[pos].lazy=-1;
    }
    int mid=(tree[pos].l+tree[pos].r)/2;
    if(r<=mid)
    update(l,r,change,pos*2);
    else if(l>mid)
    update(l,r,change,pos*2+1);
    else
    {
        update(l,mid,change,pos*2);
        update(mid+1,r,change,pos*2+1);
    }
    tree[pos].num=tree[pos*2].num+tree[pos*2+1].num;
}
int query(int l,int r,int pos)
{
    //cout<<l<<" "<<r<<" "<<pos<<endl;
    if(tree[pos].l==l&&tree[pos].r==r)
    return tree[pos].num;
    if(tree[pos].lazy==0)
    {
        tree[pos*2].num=0;
        tree[pos*2+1].num=0;
        tree[pos*2].lazy=0;
        tree[pos*2+1].lazy=0;
        tree[pos].lazy=-1;
    }
    int mid=(tree[pos].l+tree[pos].r)/2;
    if(l>mid)
    return query(l,r,pos*2+1);
    else if(r<=mid)
    return query(l,r,pos*2);
    else
    return query(l,mid,pos*2)+query(mid+1,r,pos*2+1);
}
int main()
{
    int x,q,i,t;
    while(~scanf("%d",&x))
    {
        scanf("%d",&q);
        build_tree(1,x,1);
        while(q--)
        {
            int flag,change=0,l,r;
            scanf("%d%d",&l,&r);
            update(l,r,change,1);
            printf("%d\n",query(1,x,1));
        }
    }
    return 0;
}