【hdu 6161】Big binary tree（二叉树、dp）

#include <cstdio>
#include <algorithm>
#include <map>
using namespace std;
#define mem(a,b) memset(a,b,sizeof(a))
typedef long long ll;
const ll mod=1000000007;
const int N=201000;
map<int,ll>dp,val;
int n,m;
char o[10];
ll get(int u){
	return val.count(u)?val[u]:u;
}
ll cal(int u){
	if(!u||u>n)return 0;
	if(dp.count(u))return dp[u];
	int v,ls=0,rs=0;
	for(v=u;v<=n;++ls,v<<=1);
	for(v=u;v<=n;++rs,v=v<<1|1);
	if(ls!=rs) v=n;
	else v>>=1;
	ll ans=0;
	for(;v>=u;ans+=v,v>>=1);
	return ans;
}
void update(int u,ll x){
	val[u]=x;
	while(u){
		dp[u]=max(cal(u<<1),cal(u<<1|1))+get(u);
		u>>=1;
	}
}
ll query(int u){
	ll ans=get(u)+cal(u<<1)+cal(u<<1|1);
	ll tot=cal(u);
	while(u){
		ans=max(ans,tot+cal(u^1)+get(u>>1));
		u>>=1;tot+=get(u);
	}
	return ans;
}
int main() {
	while(~scanf("%d%d",&n,&m)){
		dp.clear();val.clear();//又忘记了。。
		while(m--){
			int u;ll x;
			scanf("%s%d",o,&u);
			if(o[0]=='q'){
				printf("%lld\n",query(u));
			}else{
				scanf("%lld",&x);
				update(u,x);
			}
		}
	}
	return 0;
}