[python][c++]逆順(降順)リストにbisect(*_bound)をする

bisectは降順リストに対応してないので作ってみた。
https://codeday.me/jp/qa/20190215/252510.html
もあるけど自力実装するのもなんだかなと。

from bisect import*

cargo=[1,4,6,43,7,3,6,3,7,32]
length=len(cargo)
cargo_ascending =[1,3,3,4,6,6,7,7,32,43]
cargo_descending=[43,32,7,7,6,6,4,3,3,1]

#cargo_descending引数にとる必要ないんだけど一応
def bisect_reverse_right(cargo_descending,x,lb=0,ub=length):  
    return length-bisect_left(cargo_ascending,x,length-ub,length-lb)

def bisect_reverse_left(cargo_descending,x,lb=0,ub=length):
    return length-bisect_right(cargo_ascending,x,length-ub,length-lb)

print(bisect_left(cargo_ascending,7))  #6
print(bisect_right(cargo_ascending,7))  #8
print(bisect_left(cargo_ascending,43))  #9
print(bisect_right(cargo_ascending,43))  #10

print(bisect_reverse_left(cargo_descending,7))  #2
print(bisect_reverse_right(cargo_descending,7))  #4
print(bisect_reverse_left(cargo_descending,43))  #0
print(bisect_reverse_right(cargo_descending,43))  #1

int bisect_reverse_left(vector<int>cargo_descending,int x,int lb=0,int ub=length){
    return length-(upper_bound(cargo_ascending.begin()+length-ub,cargo_ascending.begin()+length-lb,x)-cargo_ascending.begin());
}
int bisect_reverse_right(vector<int>cargo_descending,int x,int lb=0,int ub=length){
    return length-(lower_bound(cargo_ascending.begin()+length-ub,cargo_ascending.begin()+length-lb,x)-cargo_ascending.begin());
}

コメントをいただいたので比較関数を使った版を

#include <algorithm>
#include <iostream>
#include <vector>

int length;

//こちらはcargo_descendingだけ必要
int bisect_reverse_left(std::vector<int>cargo_descending,int x,int lb=0,int ub=length){
    return *std::upper_bound(cargo_descending.begin()+lb,cargo_descending.begin()+ub, x, [](auto a, auto b) { return a > b; });
}
int bisect_reverse_right(std::vector<int>cargo_descending,int x,int lb=0,int ub=length){
    return *std::lower_bound(cargo_descending.begin()+lb,cargo_descending.begin()+ub, x, [](auto a, auto b) { return a > b; });
}



int main() {
    std::vector<int> v = {5, 4, 3, 2, 2, 1};
    length=v.size();
    std::cout<<bisect_reverse_left(v,3)<<std::endl;  //2
    std::cout<<bisect_reverse_right(v,3)<<std::endl;  //3
}