【树状数组 + 简单题】杭电 hdu 1166 敌兵布阵

/* THE PROGRAM IS MADE BY PYY */
/*----------------------------------------------------------------------------//
              Copyright (c) 2011 panyanyany All rights reserved.

    URL   : http://acm.hdu.edu.cn/showproblem.php?pid=1166
    Name  : 1166 敌兵布阵
    Date  : Sunday, September 18, 2011
    Time Stage : half an hour

    Result: 
4622505	2011-09-18 14:51:36	Accepted	1166
31MS	412K	1406 B
C++	pyy小号


    Test Data :

Review :
第二次做，理解了树状数组的原理，其实是很简单的
//----------------------------------------------------------------------------*/

#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
#include <string.h>

#define MAXSIZE 50001

int tcase, n ;
int tree[MAXSIZE] ;

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

void add (int pos, int val)
{
	while (pos <= n)
	{
		tree[pos] += val ;
		pos += lowbit (pos) ;
	}
}

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

int main ()
{
	char	str[20] ;
	int		i, j ;
	int		x, y ;

	while (scanf ("%d", &tcase) != EOF)
	{
		for (j = 1 ; j <= tcase ; ++j)
		{
			memset (tree, 0, sizeof (tree)) ;
			scanf ("%d", &n) ;
			for (i = 1 ; i <= n ; ++i)
			{
				scanf ("%d", &x) ;
				add (i, x) ;
			}
			printf ("Case %d:\n", j) ;
			while (scanf ("%s", str), *str != 'E')
			{
				scanf ("%d%d", &x, &y) ;
				if (*str == 'Q')
					printf ("%d\n", getSum (y) - getSum (x - 1)) ;
				else if (*str == 'A')
					add (x, y) ;
				else if (*str == 'S')
					add (x, -y) ;
			}
		}
	}
	return 0 ;
}