HDU 1166 敌兵布阵

(更新点查询区间)

好吧，今天算是被这道题坑惨了，TLE了许久，结果发现原来就是用了一个cout的原因。。改成printf后一下就过了，而且时间一下缩短数倍。。俗话说，吃一堑，长一智，，我算是长记性了。。

 

代码：

#include <iostream>   
#include <cstdio>   
#include <cstring>   
#include <cmath>   
#include <algorithm>   
#include <cstdlib>   

using namespace std;    
#define N 50011

int tree[4*N];

int a[N];

void build(int l,int r,int rt)
{
    if(l==r)
    {
        scanf("%d",&tree[rt]);
        return;
    }
    int mid = (l+r)/2;
    build(l,mid,2*rt);
    build(mid+1,r,2*rt+1);
    tree[rt] = tree[2*rt] + tree[2*rt+1];
}

void update(int l,int r,int pos,int val,int rt)
{
    if(l==r)
    {
        tree[rt] += val;
        return;
    }
    int mid = (l+r)/2;
    if(pos<=mid)
        update(l,mid,pos,val,2*rt);
    else
        update(mid+1,r,pos,val,2*rt+1);
    tree[rt] = tree[2*rt] + tree[2*rt+1];
}

int query(int l,int r,int aa,int bb,int rt)
{
    if(aa>r||bb<l)
        return 0;
    if(aa<=l&&bb>=r)
        return tree[rt];
    int mid = (l+r)/2;
    if(bb<=mid)
        return query(l,mid,aa,bb,2*rt);
    else if(aa>mid)
        return query(mid+1,r,aa,bb,2*rt+1);
    return query(l,mid,aa,bb,2*rt)+query(mid+1,r,aa,bb,2*rt+1);
}

int main()
{
    int t,n,i;
    char ss[10];
    int aa,bb;
    scanf("%d",&t);
    int cs = 1;
    while(t--)
    {
        memset(tree,0,sizeof(tree));
        scanf("%d",&n);
        build(1,n,1);
        printf("Case %d:\n",cs++);
        while(scanf("%s",ss)&&ss[0]!='E')
        {
            scanf("%d%d",&aa,&bb);
            if(ss[0] == 'A')
                update(1,n,aa,bb,1);
            else if(ss[0] == 'S')
                update(1,n,aa,-bb,1);
            else if(ss[0] == 'Q')
            {
                int ans = query(1,n,aa,bb,1);
                printf("%d\n",ans);   //Don't use cout!
            }
        }
        
    }
    return 0;
}