hdu1166 敌兵布阵

似乎当初就是学到这里然后自己就去乱搞了？然后就弃坑了？想想挺难受的其实

树状数组板子题。初始化wa了一发

#include<cstdio>
#include<cstring>
#include<iostream>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
#define mem(a,b) memset(a,b,sizeof(a))
#define ll long long
#define inf 1000000000
#define maxn 40000
#define eps 1e-12
#define mod 1000000007
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9') {if(ch=='-') f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') {x=10*x+ch-'0';ch=getchar();}
    return x*f;
}
int a[50005],n;
char s[20];
int lowbit(int i)
{
    return i&(-i);
}
void update(int i,int peo)
{
    while(i<=n)
    {
        a[i]+=peo;i+=lowbit(i);
    }
}
int sum(int i)
{
    int sum=0;
    while(i>0)
    {
        sum+=a[i];
        i-=lowbit(i);
    }
    return sum;
}
int main()
{
    int T;
    T=read();
    int num=1,peo;
    while(T--)
    {
        n=read();
        mem(a,0);
        for(int i=1;i<=n;++i)  peo=read(),update(i,peo);
        printf("Case %d:
",num++);
        while(scanf("%s",s))
        {
            if(s[0]=='E') break;
            int x,y;
            x=read();y=read();
            if(s[0]=='Q') printf("%d
",sum(y)-sum(x-1));
            else if(s[0]=='A') update(x,y);
            else update(x,-y);
        }
    }
    return 0;
}