HDU 1166 敌兵布阵

#include <iostream>
#include <cstring>
#define MAXSIZE 500000
using namespace std;

struct node
{
    int l,r;
    int sum;
}tree[MAXSIZE*4];

int num[MAXSIZE];

void build(int root,int l,int r)
{
    tree[root].r = r;
    tree[root].l = l;
    
    
    if(l==r)
    {
        tree[root].sum = num[l];
        return;
    }
    
    int mid = (r+l)/2;
    
    build(root*2,l,mid);
    build(root*2+1,mid+1,r);
    tree[root].sum = tree[root*2].sum + tree[root*2+1].sum;
}

void update(int root,int pos,int value)
{
    if(tree[root].r==tree[root].l&&tree[root].r==pos)
    {
        tree[root].sum+=value;
        return;
    }
    
    int mid = (tree[root].r+tree[root].l)/2;
    
    if(pos<=mid)
    {
        update(root*2,pos,value);
    }
    else
    {
        update(root*2+1,pos,value);
    }
    tree[root].sum = tree[root*2].sum + tree[root*2+1].sum;
}


int query(int root,int l,int r)
{
    if(r>=tree[root].r&&l<=tree[root].l)
        return tree[root].sum;
    
    int mid = (tree[root].r+tree[root].l)/2;    
    if(r<=mid)
    {
        return query(root*2,l,r);
    }
    else if(l>mid)
    {
        return query(root*2+1,l,r);
    }
    else
    {
        int a = query(root*2,l,mid);
        int b = query(root*2+1,mid+1,r);
        return a+b;
    }
}



int main()
{
    int test;
    int n;
    char t[8];
    scanf("%d",&test);
    int a,b;
//    freopen("data.txt","r",stdin);
    for(int k=1;k<=test;k++)
    {
        scanf("%d",&n);
        
        for(int i=1;i<=n;i++)
        {
            scanf("%d",num+i);
        }
        
        build(1,1,n);
        
        printf("Case %d:\n",k);
        
        while(scanf("%s",t)&&strcmp(t,"End")!=0)
        {
            scanf("%d %d",&a,&b);
            if(strcmp(t,"Query")==0)
            {
                printf("%d\n",query(1,a,b));
            }
            else if(strcmp(t,"Add")==0)
            {
                update(1,a,b);
            }
            else if(strcmp(t,"Sub")==0)
            {
                update(1,a,-b);
            }
            
        }        
    }

    return 0;
}