C++一些不常见的库及函数

pbds库 平衡树：one , two

#include <bits/extc++.h>
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> set_t;
struct data{
    int x,r,f;
    data(int _x=0,int _r=0,int _f=0):x(_x),r(_r),f(_f){}
    bool operator<(const data& b)const{
        if(x!=b.x)return x<b.x;
        return f>b.f;
    }
}a[SIZE];
set_t s[10021];
int main(){
    DRII(n,K);
    REP(i,n){
        DRIII(x,r,f);f+=10;
        a[i]=data(x,r,f);
        a[i+n]=data(x+r,x,-f);
    }
    sort(a,a+2*n);
    LL an=0;
    REP(i,2*n){
        if(a[i].f>0){
            REPP(j,a[i].f-K,a[i].f+K+1){
                an+=SZ(s[j])-s[j].order_of_key(a[i].x-a[i].r);
            }
            s[a[i].f].insert(a[i].x);
        }
        else{
            s[-a[i].f].erase(a[i].r);
        }
    }
    cout<<an<<endl;
    return 0;
}
/* 
int main() {
    set_t s;
    for ( int i=0; i<5; i++ ) s.insert(10*i);
    assert(*s.find_by_order(0) == 0);
    assert(*s.find_by_order(3) == 30);
    assert(s.find_by_order(5) == s.end());
    assert(s.order_of_key(0) == 0);
    assert(s.order_of_key(30) == 3);
    assert(s.order_of_key(35) == 4);
    assert(s.order_of_key(100) == 5);
    return 0;
}
*/