hdu1166

没有用到懒惰标记的线段树问题，不过通过这道题找到了不用数组就能找到写update的方法了

#include<iostream>
#include<queue>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
#define max 50010
#define INF 0x3f3f3f3f
int tree[max*3],ans;

void build(int rt,int L,int R)
{
    if(L== R)
    {
        scanf("%d",&tree[rt]);
    }
    else
    {
        int M = (L+R)/2;
        build(rt*2,L,M);
        build(rt*2+1,M+1,R);
        tree[rt]= tree[rt*2]+tree[rt*2+1];
    }
}


void update(int rt,int L,int R,int p,int q)
{
    if(L==R&&L == p)
    {
        tree[rt]+= q;
    }
    else
    {
        int M = (L+R)/2;
        if (p<=M) update(rt*2,L,M,p,q);
        else
        update(rt*2+1,M+1,R,p,q);
        tree[rt]= tree[rt*2]+tree[rt*2+1];
    }
}


void query(int cur,int x,int y,int s,int t)
{
    int mid = (x+y)>> 1,ls = cur<< 1,rs  =cur<<1|1;
    if(x>= s&&y<= t)
    {
        ans += tree[cur];
        return ;
    }
    //pushdown(cur,x,y);
    if(mid>= s)
      query(ls,x,mid,s,t);
    if(mid+1<= t)
      query(rs,mid+1,y,s,t);
}


int main()
{

    int n,a,b,c,count =0;scanf("%d",&n);
    while(n--)
    {
        memset(tree,0,sizeof(tree));
        ans =0;
        count++;
        scanf("%d",&a);
        build(1,1,a);
        char s[10];
        printf("Case %d:
",count);
        while((scanf("%s",s)!= EOF)&&s[0]!='E')
        {
            ans =0;
            scanf("%d%d",&b,&c);
            if(s[0]=='Q'){query(1,1,a,b,c);printf("%d
",ans);}
            else if(s[0]=='A'){
                update(1,1,a,b,c);
            }
            else update(1,1,a,b,-c);
        }

    }
    return 0;
}