【HDU】1166 敌兵布阵

#include<cstdio>
#include<cstring>
#define MAXN 50010
int tree[MAXN<<2];
inline void PushUp(int rt)
{
    tree[rt]=tree[rt<<1]+tree[rt<<1|1];
}
void Build(int L,int R,int rt)
{
    if(L==R)
        scanf("%d",&tree[rt]);
    else
    {
        int mid=(L+R)>>1;
        Build(L,mid,rt<<1);
        Build(mid+1,R,rt<<1|1);
        PushUp(rt);
    }
}
void Update(int x,int val,int L,int R,int rt)
{
    if(L==R)
        tree[rt]+=val;
    else
    {
        int mid=(L+R)>>1;
        if(x<=mid)
            Update(x,val,L,mid,rt<<1);
        else
            Update(x,val,mid+1,R,rt<<1|1);
        PushUp(rt);
    }
}
int Query(int x,int y,int L,int R,int rt)
{
    if(x<=L&&R<=y)
        return tree[rt];
    int mid,ans;
    mid=(L+R)>>1;
    ans=0;
    if(mid>=x)
        ans+=Query(x,y,L,mid,rt<<1);
    if(mid<y)
        ans+=Query(x,y,mid+1,R,rt<<1|1);
    return ans;
}
int main()
{
    char cmd[10];
    int c,n,x,y,ca=1;
    scanf("%d",&c);
    while(c--)
    {
        scanf("%d",&n);
        Build(1,n,1);
        printf("Case %d:\n",ca++);
        while(scanf(" %s",cmd),strcmp(cmd,"End"))
        {
            scanf("%d%d",&x,&y);
            if(!strcmp(cmd,"Add"))
                Update(x,y,1,n,1);
            else if(!strcmp(cmd,"Sub"))
                Update(x,-y,1,n,1);
            else
                printf("%d\n",Query(x,y,1,n,1));
        }
    }
    return 0;
}