hdu 敌兵布阵

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1166

BIT简单应用，加减，求和操作。   自己没有注意每次数组归零，果断傻逼的交了好多次，WA啊......  Orz

代码：

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
#include <iostream>
#include <ctype.h>
#include <iomanip>
#include <queue>
#include <stdlib.h>
using namespace std;

int s[50005];
int t,n,m,p,i,j;

int lowbit(int x)
{
    return x&(-x);
}

void add(int x, int d){
    while (x <= n){
        s[x] += d;
        x += lowbit(x);
    }
}

int sum(int x){
    int ans = 0;
    while (x > 0){
        ans += s[x];
        x -= lowbit(x);
    }
    return ans;
}

int main()
{
    
    scanf("%d",&t);
    for(m=1; m<=t;m++){
        printf("Case %d:
",m);
        scanf("%d",&n);
        memset(s,0,sizeof(s));
        for (i = 1; i <= n; i++){
            scanf("%d", &p);
            add(i, p);
        }
        char str[10];
        
    while(~scanf("%s",&str)){
        int x,y;
        if(strcmp(str,"Add")==0){
            scanf("%d%d",&x,&y);
            add(x,y);
        }
        else if(strcmp(str,"Sub")==0){
            scanf("%d%d",&x,&y);
            add(x,-y);
        }
        else if(strcmp(str,"Query")==0){
            scanf("%d %d",&x,&y);
            printf("%d
",sum(y)-sum(x-1));
        }
        if(strcmp(str,"End")==0){
            break;
        }
    }
    }
}