题解 | #二叉树#

#include<cstdio>
int tree(int m,int n){
    if(m > n){
        return 0;
    }else{
        return 1+tree(2*m,n)+tree(2*m+1,n);
    }

}
int main(){
    int m, n ;
    while(scanf("%d%d",&m,&n) != EOF){
        if(0 == m){
            break;
        }else{
            printf("%d\n",tree(m,n));
        }
    }
}