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| #include <bits/stdc++.h>
using namespace std;
const int MAXN = 110000,LOGN = 31;
namespace Tree{
int sumn[MAXN*LOGN],ls[MAXN*LOGN],rs[MAXN*LOGN],cnt = 1;
void upd(int nown,int v){
static int tmp[40];int ecnt = 0;
for(int i = nown;i;i>>=1) tmp[++ecnt] = i&1;
int now = 1;
for(int i = ecnt-1;i>=0;--i){
sumn[now] += v;
if(tmp[i] == 0){
if(!ls[now]) ls[now] = ++cnt;
now = ls[now];
}
else{
if(!rs[now]) rs[now] = ++cnt;
now = rs[now];
}
}
}
double decay(){
int now = 1,nowmax = -1e9;
double ans = 0, p = 1;
while(now != 0){// now 非空
int lson = sumn[ls[now]],rson = sumn[rs[now]],val = sumn[now] - lson - rson;
p *= 0.5;
ans += p * max(nowmax,max(lson,rson)+val);
if(lson > rson){
nowmax = max(nowmax,rson+val);
now = ls[now];
}
else{
nowmax = max(nowmax,lson+val);
now = rs[now];
}
}
ans += p * nowmax;
return ans;
}
}
int h,q;
void init(){
scanf("%d %d",&h,&q);
}
void solve(){
for(int i = 1;i<=q;i++){
char s[12];
int a,b;
scanf("%s",s);
if(s[0] == 'a'){
scanf("%d %d",&a,&b);
Tree::upd(a,b);
}
else if(s[0] == 'd'){
printf("%.8lf\n",Tree::decay());
}
}
}
int main(){
init();
solve();
return 0;
}
|
