HDU 1166 敌兵布阵

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

解析：

树状数组

基础知识：http://blog.csdn.net/mullerwch/article/details/38382831

/*
ID:muller8
Name: 1166  敌兵布阵
Reference:树状数组
*/

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
#define MAXN 50005
#define INF 1e9

int c[MAXN];
int N;

int lowbit(int n){
    return n&(n^(n-1));
}

void ADD(int p, int k){
    while(p<=N){
        c[p] += k;
        p += lowbit(p);
    }
}

int getsum(int p){
    int sum = 0;
    while(p>0){
        sum += c[p];
        p -= lowbit(p);
    }
    return sum;
}

int main(){
    int T;
    int Case = 0;
    scanf("%d", &T);
    while(T--){
        scanf("%d", &N);
        int i;
        memset(c, 0, sizeof(c));
        for(i=1; i<=N; ++i){
            int k;
            scanf("%d", &k);
            ADD(i, k);
        }

        printf("Case %d:\n", ++Case);
        char str[10];
        int m,n;
        while(~scanf("%s", str), str[0]!='E'){
            scanf("%d%d", &m, &n);
            if(str[0]=='A'){
                ADD(m, n);
            }
            if(str[0]=='S'){
                ADD(m, -n);
            }
            if(str[0]=='Q'){
                printf("%d\n", getsum(n) - getsum(m-1));
            }
        }
    }
    return 0;
}