HDU - 6161 Big binary tree

#include<bits/stdc++.h>
#define LL long long
using namespace std;

int n, m, max_dep;
map<int, LL> Map, pval;
char op[10];

void init() {
    Map.clear();
    pval.clear();
    max_dep = 0;
}

LL get(int x) {
    if(x > n) return 0;
    int cur = x;
    auto it = Map.find(x);
    if(it != Map.end()) return it->second;
    LL ret = 0;
    int depth = 0;
    while((1 << depth) <= x) depth++;
    while(x <= n) {
        ret += x;
        if((++depth) > max_dep) break;
        LL lval = (x << 1) << (max_dep - depth);
        LL rval = (x << 1 | 1) << (max_dep - depth);
        if(lval <= n && rval <= n || lval > n && lval > n) x = (x << 1 | 1);
        else x = (x << 1);
    }
    return Map[cur] = ret;
}

LL getP(int x) {
    auto it = pval.find(x);
    if(it != pval.end()) return it->second;
    return x;
}

void modify(int x, LL val) {
    LL lval, rval;
    pval[x] = val;
    while(x) {
        lval = get(x << 1);
        rval = get(x << 1 | 1);
        Map[x] = max(lval, rval) + getP(x);
        x /= 2;
    }
}

LL query(int x) {
    LL ret = get(x << 1) + get(x << 1 | 1) + getP(x);
    LL now = get(x);
    int pa = x >> 1;
    while(pa) {
        now += getP(pa);
        if(x & 1) ret = max(ret, get(pa << 1) + now);
        else ret = max(ret, get(pa << 1 | 1) + now);
        x >>= 1;
        pa >>= 1;
    }
    return ret;
}

int main() {
    while(scanf("%d%d", &n, &m) != EOF) {
        init();
        while((1 << max_dep) <= n) max_dep++;
        while(m--) {
            scanf("%s", op);
            if(*op == ‘c‘) {
                int u, x;
                scanf("%d%d", &u, &x);
                modify(u, x);
            }
            else {
                int u; scanf("%d", &u);
                printf("%lld\n", query(u));
            }
        }
    }
    return 0;
}

/*
*/