hdu 4027 Can you answer these queries?

题目链接如下所示：

Problem - 4027

线段树裸题。有剪枝的优化空间。

代码如下所示：

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<ctime>
#include<vector>
#include<algorithm>
#include<cstring>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<string>
#include<cmath>
#include<climits>

using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
typedef long long ll;
const int MAXN=100001;
ll sum[MAXN<<2];

void push_up(int rt){
    sum[rt]=sum[rt<<1]+sum[rt<<1|1];
}

void build(int l,int r,int rt){
    if (l==r){
        scanf("%lld",&sum[rt]);
        return;
    }
    int mid=(l+r)>>1;
    build(lson);
    build(rson);
    push_up(rt);
}

void update(int a,int b,int l,int r,int rt){
//    if (a<=l && r<=b && sum[rt]==r-l+1) return;
    if (l==r){
        sum[rt]=(ll)sqrt(sum[rt]);
        return;
    }
    int mid=(l+r)>>1;
    if (a<=mid){
        update(a,b,lson);
    }
    if (b>mid){
        update(a,b,rson);
    }
    push_up(rt);
}

ll query(int a,int b,int l,int r,int rt){
    if (a<=l && r<=b) return sum[rt];
    ll res=0;
    int mid=(l+r)>>1;
    if (a<=mid){
        res+= query(a,b,lson);
    }
    if (b>mid){
        res+= query(a,b,rson);
    }
    return res;
}

int main(){
    int n,m,op,a,b;
    int k=1;
    while (~scanf("%d",&n)){
        printf("Case #%d:\n",k++);
        build(1,n,1);
        scanf("%d",&m);
        for (int i = 1; i <= m; ++i) {
            scanf("%d %d %d",&op,&a,&b);
//            cout<<op<<","<<a<<","<<b<<endl;
            if (a>b) swap(a,b);
            if (op==0){
                update(a,b,1,n,1);
            } else{
                printf("%lld\n", query(a,b,1,n,1));
            }
        }
        printf("\n");
    }
    return 0;
}