hdu1166 敌兵布阵 (树状数组)

#include <stdio.h>
#include <string.h>
#define MAX 1000005

int arr[MAX],n;
//树状数组
int lowBit(int x)//二进制后面为0的个数
{
	return (x&(-x));
}

void add(int index,int val)//将index位置的值+val
{
	while(index<=n)
	{
		arr[index]+=val;
		index+=lowBit(index);
	}
}

int func(int num)
{
	int sum=0;
	while(num>0)
	{
		sum+=arr[num];
		num-=lowBit(num);//找到num前的所有最大子树 
	}
	return sum;
}
int main()
{
	int test,i,s,t,ai,cases=1;
	char cmd[10];
	scanf("%d",&test);
	while(test--)
	{
		memset(arr,0,sizeof(arr));
		printf("Case %d:\n",cases++);
		scanf("%d",&n);
		for(i=1;i<=n;i++)
		{
			scanf("%d",&ai);
			add(i,ai);
		}
		while(scanf("%s",cmd))
		{
			if(cmd[0]=='E')
				break;
			scanf("%d %d",&s,&t);
			if(cmd[0]=='A')
				add(s,t);
			else if(cmd[0]=='S')
				add(s,-t);
			else
				printf("%d\n",func(t)-func(s-1));
		}
	}
	return 0;
}

//线段树
#include <stdio.h>

int sum[200002];

void pushUP(int root)
{
	sum[root]=sum[root<<1]+sum[root<<1|1];
}

void build(int left,int right,int root)
{
	int mid;
	if(left==right)
	{
		scanf("%d",&sum[root]);
		return;
	}
	mid=(left+right)>>1;
	build(left,mid,root<<1);
	build(mid+1,right,root<<1|1);
	pushUP(root);
}

void updata(int p,int add,int left,int right,int root)
{
	int mid;
	if(left==right)
	{
		sum[root]+=add;
		return;
	}
	mid=(left+right)>>1;
	if(p<=mid)
		updata(p,add,left,mid,root<<1);
	else
		updata(p,add,mid+1,right,root<<1|1);
	pushUP(root);
}

int query(int st,int end,int left,int right,int root)
{
	int mid,ans=0;
	if(st<=left&&end>=right)
		return sum[root];
	mid=(left+right)>>1;
	if(st<=mid)
		ans+=query(st,end,left,mid,root<<1);
	if(end>mid)
		ans+=query(st,end,mid+1,right,root<<1|1);
	return ans;
}

int main()
{
	int test,n,x,y,i;
	char cmd[10];
	scanf("%d",&test);
	for (i=1;i<=test;i++)
	{
		printf("Case %d:\n",i);
		scanf("%d",&n);
		build(1,n,1);
		while(scanf("%s",cmd)&&cmd[0]!='E')
		{
			scanf("%d %d",&x,&y);
			if(cmd[0]=='Q')
				printf("%d\n",query(x,y,1,n,1));
			else if(cmd[0]=='S')
				updata(x,-y,1,n,1);
			else
				updata(x,y,1,n,1);
		}
	}
	return 0;
}