hdu 3473 Minimum Sum 划分树

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <string>

#define CL(a,num) memset((a),(num),sizeof(a))
#define iabs(x)  ((x) > 0 ? (x) : -(x))
#define Min(a , b) ((a) < (b) ? (a) : (b))
#define Max(a , b) ((a) > (b) ? (a) : (b))

#define ll __int64
#define inf 0x7f7f7f7f
#define MOD 100000007
#define lc l,m,rt<<1
#define rc m + 1,r,rt<<1|1
#define pi acos(-1.0)
#define test puts("<------------------->")
#define maxn 100007
#define M 100007
#define N 100007
using namespace std;
//freopen("din.txt","r",stdin);

struct node{
int l,r;
int mid(){
return (l + r)>>1;
}
}tt[N<<2];

int toLeft[20]
;
int sorted
,val[20]
;
ll Lsum[20]
,sum
;
ll lnum,rnum,lsum,rsum;

int n,m;

void build(int l,int r,int rt,int d){
int i;
tt[rt].l = l;
tt[rt].r = r;
if (l == r) return ;

int m = tt[rt].mid();
int lsame = m - l + 1;
for (i = l; i <= r; ++i){
if (val[d][i] < sorted[m]){
lsame--;
}
}
int lpos = l, rpos = m + 1;
int same = 0;
for (i = l; i <= r; ++i){
if (i == l){
toLeft[d][i] = 0;
Lsum[d][i] = 0;
}
else{
toLeft[d][i] = toLeft[d][i - 1];
Lsum[d][i] = Lsum[d][i - 1];
}

if (val[d][i] < sorted[m]){
toLeft[d][i]++;
Lsum[d][i] += val[d][i];
val[d + 1][lpos++] = val[d][i];
}
else if (val[d][i] > sorted[m]){
val[d + 1][rpos++] = val[d][i];
}
else{
if (same < lsame){
same++;
toLeft[d][i]++;
Lsum[d][i] += val[d][i];
val[d + 1][lpos++] = val[d][i];
}
else{
val[d + 1][rpos++] = val[d][i];
}
}
}
build(lc,d + 1);
build(rc,d + 1);
}
int query(int L,int R,int k,int d,int rt){
ll tmp = 0;//记录小于第k大数的所有数的和
if (L == R){
//lnum++;
//lsum += val[d][L];//这里可有可无因为求的时候它始终是0
return val[d][L];
}

int s,ss;
if (L == tt[rt].l){
ss = 0;
s = toLeft[d][R];
tmp = Lsum[d][R];
}
else{
ss = toLeft[d][L - 1];
s = toLeft[d][R] - toLeft[d][L - 1];
tmp = Lsum[d][R] - Lsum[d][L - 1];
}

if (s >= k){
int newl = tt[rt].l + ss;
int newr = newl + s - 1;
return query(newl,newr,k,d + 1,rt<<1);
}
else{
lnum += s;//个数
lsum += tmp;//和
int m = tt[rt].mid();
int bb = L - tt[rt].l - ss;
int b = R - L + 1 - s;
int newl = m + bb + 1;
int newr = newl + b - 1;
return query(newl,newr,k - s,d + 1,rt<<1|1);
}
}
int main(){
// freopen("din.txt","r",stdin);
int t,cas = 1;
int i;
int x,y;
scanf("%d",&t);
while (t--){
printf("Case #%d:\n",cas++);
scanf("%d",&n);
sum[0] = 0;
for (i = 1; i <= n; ++i){
scanf("%d",&val[0][i]);
sum[i] = sum[i - 1] + val[0][i];
sorted[i] = val[0][i];
}
//for (i = 1; i <= n; ++i) printf("")
sort(sorted + 1,sorted + 1 + n);
build(1,n,1,0);//建树

scanf("%d",&m);

while (m--){
scanf("%d%d",&x,&y);
x++; y++;
int k = (y - x + 1);
if (k&1) k = k/2 + 1;
else k = k/2;//求出k
lnum = 0;
lsum = 0;
ll ave = query(x,y,k,0,1);
rsum = sum[y] - sum[x - 1] - lsum;//所有大于ave的和
rnum = y - x + 1 - lnum;//大于ave的个数
ll ans = rsum - rnum*ave + lnum*ave - lsum;
printf("%I64d\n",ans);
}
printf("\n");
}
return 0;
}