Manthan, Codefest 19 (open for everyone, rated, Div. 1 + Div. 2) D - Restore Permutation（线段树维护前缀和）

https://codeforc.es/contest/1208/problem/D

线段树维护从1到n的前缀和，从后往前查询第一个前缀和大于ai的位置，线段树简单操作我竟然没当场写出来555

 1 #define bug(x) cout<<#x<<" is "<endl
 2 #define IO std::ios::sync_with_stdio(0)
 3 #include 
 4 #define iter ::iterator
 5 #define pa pair<int,ll>
 6 using namespace  std;
 7 #define ll long long
 8 #define mk make_pair
 9 #define pb push_back
10 #define se second
11 #define fi first
12 #define ls o<<1
13 #define rs o<<1|1
14 ll mod=998244353;
15 const int N=2e5+5;
16 ll a[N];
17 ll mx[N*4],lz[N*4];
18 void down(int o){
19     if(lz[o]){
20         mx[ls]+=lz[o];
21         mx[rs]+=lz[o];
22         lz[ls]+=lz[o];
23         lz[rs]+=lz[o];
24         lz[o]=0;
25     }
26 }
27 void up(int o,int l,int r,int ql,int qr,ll v){
28     if(l>=ql&&r<=qr){
29         mx[o]+=v;
30         lz[o]+=v;
31         return;
32     }
33     int m=(l+r)/2;
34     down(o);
35     if(ql<=m)up(ls,l,m,ql,qr,v);
36     if(qr>m)up(rs,m+1,r,ql,qr,v);
37     mx[o]=max(mx[ls],mx[rs]);
38 }
39 int qu(int o,int l,int r,ll v){
40     //printf("l=%d r=%d sum=%d\n",l,r,sum[o]);
41     if(l==r)return l;
42     int m=(l+r)/2;
43     down(o);
44     if(v>=mx[ls])return qu(rs,m+1,r,v);
45     return qu(ls,l,m,v);
46     mx[o]=max(mx[ls],mx[rs]);
47 }
48 int n;
49 int b[N];
50 int main(){
51     IO;
52     cin>>n;
53     for(int i=1;i<=n;i++){
54         cin>>a[i];
55     }
56     ll h=0;
57     for(int i=1;i<=n;i++){
58         h+=i;
59         up(1,1,n,i,i,h);
60     }
61     for(int i=n;i>=1;i--){
62         ll x=a[i];
63         int res=qu(1,1,n,x);
64         b[i]=res;
65         up(1,1,n,b[i],n,-b[i]);
66     }
67     for(int i=1;i<=n;i++){
68         cout<;
69     }
70 }
71 /*
72 5
73 0 1 1 1 10
74 */