题解 | #二叉树#

• 简单递归

#include<iostream>
using namespace std;
int getnum(int m,int n){
    if(m>n)return 0;
    else return getnum(2*m,n)+getnum(2*m+1,n)+1;
}
int main(){
    int m,n;
    while(scanf("%d %d",&m,&n)!=EOF){
        printf("%d\n",getnum(m,n));
    }
    return 0;
}