Codeforces 1324D（红黑树+求指定区间中大于指定值的个数）

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#define IOS ios::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define deg(x) cout<< #x"=" << (x) << endl;
#define degg(x,y) cout<< #x"="<< (x) <<","<< #y"="<< (y) <<endl;
#define deggg(x,y,z) cout<<#x"="<<(x)<<","<<#y"="<<(y)<<","<<#z"="<<(z)<<endl;
#define sca(x) scanf("%d",&x)
#define scaa(x,y) scanf("%d%d",&x,&y)
#define scaaa(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define pch(x) putchar(x)
#define ptf(x) printf("%dn",x)
#define ptff(x,y) printf("%d %dn",x,y)
#define ptfff(x,y,z) printf("%d %d %dn",x,y,z)
#define space(x) printf("%d ",x)
#define mes(a,x) memset(a,x,sizeof(a))
#define PI acos(-1)
#define lowbit(x) x&-x
#define ALL(X) (X).begin(), (X).end()
#define PB push_back
#define MP make_pair
#define ls rt<<1
#define rs rt<<1|1
#define ac(t) cout<<t<<endl
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef priority_queue<int,vector<int>,greater<int> > xqueue;
typedef priority_queue<int> dqueue;
typedef tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update> x_rb;
typedef tree<int,null_type,greater_equal<int>,rb_tree_tag,tree_order_statistics_node_update> d_rb;
const ll mod=1e9+7;
const ll INF=9e18;
const int inf=2147483647;
const int N=2e5+5;
int a[N],b[N];
int d[N],d2[N];
void work() {
int n; sca(n);
for(int i=1;i<=n;i++) {
sca(a[i]);
}
for(int j=1;j<=n;j++) {
sca(b[j]);
d[j]=a[j]-b[j];
d2[j]=b[j]-a[j];
}
d_rb rb;
ll ans=0;
for(int j=n;j;j--) {
ans+=rb.order_of_key(d2[j]); //求排第几
rb.insert(d[j]);
}
ac(ans);
}
int main() {
#ifdef Local
freopen("1.txt","r",stdin);
#endif // mm
work();
return 0;
}