学步园

TLE求错误啊啊啊啊啊啊啊

#include <iostream>
#include <cstdio>
#include <fstream>
#include <cmath>
#include <cstring>

using namespace std;

#define MAXN 50010

int ai[MAXN];
int N;
int T;

struct node
{
    int left;
    int right;
    int sum;
}Tree[MAXN<<2];

void PushUp(int root)
{
    Tree[root].sum = Tree[root<<1].sum + Tree[(root<<1)+1].sum;
}

void Build(int start,int end,int root)
{
    Tree[root].left = start;
    Tree[root].right = end;
    int mid = (start + end)>>1;
    if(start == end)
    {
        Tree[root].sum = ai[start];
        return;
    }
    Tree[root].left = start;
    Tree[root].right = end;
    Build(start,mid,root*2);
    Build(mid+1,end,root*2+1);
    PushUp(root);
    //Tree[root].sum = Tree[root<<1].sum + Tree[(root<<1)+1].sum;
}

int Query(int start,int end,int root)
{
    if(start > Tree[root].right || end < Tree[root].left)
        return 0;
    if(start<= Tree[root].left && Tree[root].right <= end)
        return Tree[root].sum;
    int mid = (start + end)>>1;
    int a = Query(start,end,root<<1);
    int b = Query(start,end,(root<<1)+1);
    return a+b;
}

void Update(int root,int pos,int value,int start,int end,int type)
{
    if(start == end)
    {
        if(type == 1)
            Tree[root].sum += value;
        if(type == 2)
            Tree[root].sum -= value;
        return;
    }
    int mid = (start + end)>>1;
    if(pos <= mid)
        Update(root<<1,pos,value,start,mid,type);
    else
        Update((root<<1)+1,pos,value,mid+1,end,type);
    PushUp(root);
}


    
int main()
{
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
    scanf("%d",&T);
    int count = 0;
    while(T--)
    {
        memset(ai,0,sizeof(ai));
        memset(Tree,0,sizeof(Tree));
        count++;
        scanf("%d",&N);
        for(int i = 1; i <= N; i++)
        {
            scanf("%d",&ai[i]);
        }
        Build(1,N,1);
        cout<<"Case "<<count<<":"<<endl;
        char oper[11];
        int i,j;
        while(scanf("%s",oper))
        {
            if(strcmp(oper,"End")==0)
                break;
            cin>>i>>j;
            if(strcmp(oper,"Query")==0)
                cout<<Query(i,j,1)<<endl;
            if(strcmp(oper,"Add")==0)
            {
                ai[i] += j;
                Update(1,i,j,1,N,1);
            }
            if(strcmp(oper,"Sub")==0)
            {
                ai[i] -= j;
                Update(1,i,j,1,N,2);
            }
        }
    }
    return 0;
}