hdu1166 敌兵布阵 线段树

#include <iostream>
#include <cstdio>
#include <fstream>
#include <cmath>
#include <cstring>

using namespace std;

#define MAXN 50010

int ai[MAXN];
int N;
int T;

struct node
{
int left;
int right;
int sum;
}Tree[MAXN<<2];

void PushUp(int root)
{
Tree[root].sum = Tree[root<<1].sum + Tree[(root<<1)+1].sum;
}

void Build(int start,int end,int root)
{
Tree[root].left = start;
Tree[root].right = end;
int mid = (start + end)>>1;
if(start == end)
{
Tree[root].sum = ai[start];
return;
}
Tree[root].left = start;
Tree[root].right = end;
Build(start,mid,root*2);
Build(mid+1,end,root*2+1);
PushUp(root);
//Tree[root].sum = Tree[root<<1].sum + Tree[(root<<1)+1].sum;
}

int Query(int start,int end,int root)
{
if(start > Tree[root].right || end < Tree[root].left)
return 0;
if(start<= Tree[root].left && Tree[root].right <= end)
return Tree[root].sum;
int mid = (start + end)>>1;
int a = Query(start,end,root<<1);
int b = Query(start,end,(root<<1)+1);
return a+b;
}

void Update(int root,int pos,int value,int start,int end,int type)
{
if(start == end)
{
if(type == 1)
Tree[root].sum += value;
if(type == 2)
Tree[root].sum -= value;
return;
}
int mid = (start + end)>>1;
if(pos <= mid)
Update(root<<1,pos,value,start,mid,type);
else
Update((root<<1)+1,pos,value,mid+1,end,type);
PushUp(root);
}

int main()
{
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
scanf("%d",&T);
int count = 0;
while(T--)
{
memset(ai,0,sizeof(ai));
memset(Tree,0,sizeof(Tree));
count++;
scanf("%d",&N);
for(int i = 1; i <= N; i++)
{
scanf("%d",&ai[i]);
}
Build(1,N,1);
cout<<"Case "<<count<<":"<<endl;
char oper[11];
int i,j;
while(scanf("%s",oper))
{
if(strcmp(oper,"End")==0)
break;
cin>>i>>j;
if(strcmp(oper,"Query")==0)
cout<<Query(i,j,1)<<endl;
if(strcmp(oper,"Add")==0)
{
ai[i] += j;
Update(1,i,j,1,N,1);
}
if(strcmp(oper,"Sub")==0)
{
ai[i] -= j;
Update(1,i,j,1,N,2);
}
}
}
return 0;
}