codeforces 86 D. Powerful array (莫队算法)

http://codeforces.com/problemset/problem/86/D

题意:Ks为区间内s的数目,求区间[L,R]之间所有KsKss的和

思路:莫队算法,和小z的袜子差不多。不明白第一次tle#54是什么情况。把每一块的大小改成了常数之后就过了。

再交一遍就过了。。不过貌似根据最大数据把siz大小设置成一个常数比根号n要块很多==

选区_016

  1/* ***********************************************
  2Author :111qqz
  3Created Time :2016年02月13日 星期六 23时17分58秒
  4File Name :code/cf/problem/86D.cpp
  5************************************************ */
  6
  7#include <cstdio>
  8#include <cstring>
  9#include <iostream>
 10#include <algorithm>
 11#include <vector>
 12#include <queue>
 13#include <set>
 14#include <map>
 15#include <string>
 16#include <cmath>
 17#include <cstdlib>
 18#include <ctime>
 19#define fst first
 20#define sec second
 21#define lson l,m,rt<<1
 22#define rson m+1,r,rt<<1|1
 23#define ms(a,x) memset(a,x,sizeof(a))
 24typedef long long LL;
 25#define pi pair < int ,int >
 26#define MP make_pair
 27
 28using namespace std;
 29const double eps = 1E-8;
 30const int dx4[4]={1,0,0,-1};
 31const int dy4[4]={0,-1,1,0};
 32const int inf = 0x3f3f3f3f;
 33const int N=2E5+7;
 34int t,n;
 35int a[N];
 36int pos[N];
 37LL sum;
 38LL ans[N];
 39struct node
 40{
 41    int l,r;
 42    int id;
 43
 44    bool operator <(node b)const
 45    {
 46    if (pos[l]==pos[b.l]) return r<b.r;
 47    return pos[l]<pos[b.l];
 48    }
 49
 50}q[N];
 51
 52int cnt[N*5];
 53
 54
 55void update(int x,int d)
 56{
 57    sum -= 1LL*cnt[a[x]]*cnt[a[x]]*a[x];
 58    cnt[a[x]]+=d;
 59    sum += 1LL*cnt[a[x]]*cnt[a[x]]*a[x];
 60}
 61int main()
 62{
 63    #ifndef  ONLINE_JUDGE 
 64    freopen("code/in.txt","r",stdin);   //TLE #54....WHY?
 65  #endif
 66
 67    cin>>n>>t;
 68    int bk = 470;
 69    for ( int i =  1 ; i <= n ; i++)
 70    {
 71        scanf("%d",&a[i]);
 72        pos[i]=(i-1)/bk;
 73    }
 74
 75    for ( int i = 1 ; i <= t ; i++) scanf("%d %d",&q[i].l,&q[i].r),q[i].id = i ;
 76    sort(q+1,q+t+1);
 77
 78    int pl = 1;
 79    int pr = 0;
 80    int id;
 81    int l;
 82    int r;
 83    ms(cnt,0);
 84    sum = 0;
 85    for ( int i = 1 ; i <= t ; i++)
 86    {
 87     //   cout<<"sum:"<<sum<<endl;
 88        id = q[i].id;
 89        l = q[i].l;
 90        r = q[i].r;
 91
 92        if (pr<r)
 93        {
 94        for ( int j = pr+1 ; j <= r ; j++)
 95            update(j,1);
 96        }
 97        else
 98        {
 99        for ( int j = r+1 ; j <= pr ; j++)
100            update(j,-1);
101        }
102        pr = r;
103
104        if (pl<l)
105        {
106        for ( int j = pl ; j <=l-1 ; j++)
107            update(j,-1);
108        }
109        else
110        {
111        for ( int j = l ; j <= pl-1 ; j++)
112            update(j,1);
113        }
114
115        pl = l;
116
117        ans[id] = sum;
118    }
119
120    for ( int i = 1 ;i <= t ; i++) printf("%lld\n",ans[i]);
121
122  #ifndef ONLINE_JUDGE  
123  fclose(stdin);
124  #endif
125    return 0;
126}