poj 2777

http://poj.org/problem?id=2777

#include<iostream>#include<cstdio>#include<cstring>using namespace std;#define N 100001struct node{int l,r;int type;int getmid(){return (l+r)>>1;}}p[4*N];bool h[N];void build(int l,int r,int id){p[id].l=l;p[id].r=r;p[id].type=1;if(l==r)return;int mid=(l+r)>>1;build(l,mid,id<<1);build(mid+1,r,id<<1|1);}void update(int l,int r,int type,int id){if(p[id].l==l&&p[id].r==r){p[id].type=type;return;}if(p[id].type==type)return;if(p[id].type>0){p[id<<1].type=p[id<<1|1].type=p[id].type;p[id].type=0;}int mid=p[id].getmid();if(r<=mid)update(l,r,type,id<<1);else if(l>mid)update(l,r,type,id<<1|1);else{update(l,mid,type,id<<1);update(mid+1,r,type,id<<1|1);}}void query(int l,int r,int id){if(p[id].type>0){h[p[id].type]=1;return;}int mid=p[id].getmid();if(r<=mid)query(l,r,id<<1);else if(l>mid)query(l,r,id<<1|1);else{query(l,mid,id<<1);query(mid+1,r,id<<1|1);}}int main(void){int n,T,Q;while(~scanf("%d%d%d",&n,&T,&Q)){build(1,n,1);while(Q--){char ch[5];scanf("%s",ch);if(ch[0]=='C'){int x,y,type;scanf("%d%d%d",&x,&y,&type);update(x,y,type,1);}else{memset(h,0,sizeof(h));int x,y;scanf("%d%d",&x,&y);query(x,y,1);int ans=0;for(int i=1;i<=T;i++)if(h[i])ans++;printf("%d/n",ans);}}}return 0;} 

lazy操作